COMPOUNDS The present invention relates to compounds that are capable of modulating GPR65. The compounds have potential therapeutic applications in the treatment of a variety of disorders, including proliferative and immune disorders. BACKGROUND TO THE INVENTION GPR65 is a Gs-coupled G protein-coupled receptor (GPCR) that is primarily expressed in immune cells and is activated by acidic extracellular pH to cause increases in cytoplasmic cyclic adenosine monophosphate (cAMP) (Wang, 2004). It has long been known that tumours typically undergo a switch in cellular metabolism from oxidative phosphorylation to aerobic glycolysis, which in turn results in an acidic extracellular microenvironment (Damaghi, 2013). Recently, it has been shown that this acidic microenvironment causes GPR65 activation in tumour-associated macrophages, resulting in an increase in cytoplasmic cAMP leading to transcription of the inducible cAMP early repressor (ICER). This, in turn, suppresses the secretion of tumour necrosis factor alpha (TNFα) to bias the macrophages toward an anti-inflammatory, tumour-permissive phenotype (Bohn, 2018). This GPR65-dependent pathway therefore appears to represent a mechanism by which tumours exploit their acidic microenvironment to evade detection by the immune system. Autoimmune diseases are also often associated with an acidic local microenvironment (for instance, an inflamed joint). Recent studies also suggest that GPR65 acts through ICER in CD4+ T cells, to suppress IL‐2 and hence bias cells toward an inflammatory Th17 phenotype, which is associated with increased pathogenicity in the context of autoimmune disease (Korn, 2009). Supporting this is the recent finding that ICER is required for Th17 differentiation (Yoshida, 2016) as well as that agonism of GPR65 leads to an increase in Th17 differentiation (Hernandez, 2018). Indeed, mutations in the GPR65 locus are associated with several autoimmune diseases, such as multiple sclerosis, ankylosing spondylitis, inflammatory bowel disease, and Crohn’s disease (Gaublomme, 2015). One recent study found that mice with CD4+ T cells lacking GPR65 were protected from developing the disease autoimmune encephalomyelitis (EAE) (Gaublomme, 2015). Thus, GPR65 appears to act through ICER to promote an anti-inflammatory and tumour- permissive phenotype in tumour associated macrophages and an inflammatory Th17 phenotype in CD4+ T cells that is associated with autoimmune disease. GPR65 signalling, therefore, represents an attractive pathway for therapeutic intervention for the treatment of both cancer and autoimmune diseases. There is therefore an ongoing need to develop new small molecule GPR65 modulators. WO2021245426 (Pathios Therapeutics Limited) discloses a series of small molecule GPR65 modulators. The present invention seeks to provide further compounds that are capable of modulating GPR65. As made clear from the above discussion, such compounds have potential therapeutic applications in the treatment of a variety of disorders, including proliferative disorders and immune disorders as well as asthma and chronic obstructive pulmonary disease. Advantageously, selected compounds according to the present invention may also exhibit one or more of the following properties: enhanced activity against GPR65 (also in native cells), better in vitro selectivity and toxicity profiles and/or enhanced oral pharmacokinetic profiles relevant to chronic once daily oral administration. STATEMENT OF INVENTION A first aspect of the invention relates to a compound of formula (Ia), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic or bicyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each independently selected from H, F, alkyl, and haloalkyl; and R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; R ₁₆ and R ₁₇ are each independently selected from H and alkyl; wherein the compound is other than 6-fluoro-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)-3,4- dihydroisoquinoline-2(1H)-carboxamide. Advantageously, the presently claimed compounds are capable of modulating GPR65, thereby rendering the compounds of therapeutic interest in the treatment of various disorders, for example, in the fields of oncology, immuno-oncology, and immunology. A second aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic or bicyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, CO ₂ -alkyl, O-aryl, NR ₁₁ R ₁₁ ’, CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ ; Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; R ₁₆ and R ₁₇ are each independently selected from H and alkyl; for use as a medicament. Another aspect of the invention relates to a compound selected from the following:

and pharmaceutically acceptable salts and solvates thereof. Another aspect of the invention relates to a pharmaceutical composition comprising a compound as described above and a pharmaceutically acceptable diluent, excipient, or carrier Another aspect of the invention relates to a compound or a pharmaceutical composition as described above for use as a medicament. Another aspect of the invention relates to a compound or a pharmaceutical composition as described above for use in treating or preventing a disorder selected from a proliferative disorder, an immune disorder, asthma, chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). Another aspect of the invention relates to a method of treating a disorder, comprising administering to a subject a compound or a pharmaceutical composition as described above. DETAILED DESCRIPTION The present invention relates to compounds that are capable of modulating GPR65. “Alkyl” is defined herein as a straight-chain or branched alkyl radical, preferably C _1-20 alkyl, more preferably C _1-12 alkyl, even more preferably C _1-10 alkyl or C _1-6 alkyl, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl. More preferably, the alkyl is a C _1-3 alkyl. As used herein, the term “aryl” refers to a C _6-12 aromatic group, which may be benzocondensed, for example, phenyl or naphthyl. Preferably, the aryl group is phenyl. “Haloalkyl” is defined herein as a straight-chain or branched alkyl radical as defined above, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, that is substituted with one or more halogen atoms (that may be the same or different), such as fluorine, chlorine, bromine, and iodine. Preferably, the haloalkyl is a C _1-20 haloalkyl, more preferably a C _1-12 haloalkyl, even more preferably a C _1-10 haloalkyl or a C _1-6 haloalkyl, or a C _1-3 haloalkyl. Preferred examples are CF ₃ and CHF ₂ , with CF ₃ being particularly preferred. “Alkoxy” is defined herein as an oxygen atom bonded to an alkyl group as defined above, for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, pentoxy and hexoxy. Preferably, the alkoxy is a C _1-20 alkoxy , more preferably a C _1-12 alkoxy, even more preferably C _1-10 alkoxy or a C _1-6 alkoxy, or a C _1-3 alkoxy. A preferred example is methoxy (–OCH ₃ ). “Haloalkoxy” is defined herein as an alkoxy group as described above substituted with one or more halogen atoms (that may be the same or different), such as fluorine, chlorine, bromine, and iodine. Preferably, the haloalkoxy is a C _1-20 haloalkoxy, more preferably a C _{1- 12} haloalkoxy, even more preferably a C _1-10 haloalkoxy or a C _1-6 haloalkoxy, or a C _1-3 haloalkoxy. “Heteroaryl” is defined herein as a monocyclic or bicyclic C _2-12 aromatic ring comprising one or more heteroatoms (that may be the same or different), such as oxygen, nitrogen or sulphur. Examples of suitable heteroaryl groups include thienyl, furanyl, pyrrolyl, pyridinyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, pyridazinyl, isoxazolyl, pyrimidinyl, pyrazinyl, triazinyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl etc. and benzo derivatives thereof, such as benzofuranyl, benzothienyl, benzimidazolyl, indolyl, isoindolyl, indazolyl etc.; or pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl etc. and benzo derivatives thereof, such as quinolinyl, isoquinolinyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl etc. “Aralkyl’ is defined herein as an alkyl group as defined above substituted by one or more aryl groups as defined above. Compounds One aspect of the invention relates to compounds of formula (Ia), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic or bicyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, CO ₂ -alkyl, O-aryl, NR ₁₁ R ₁₁ ’, CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ ; Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each independently selected from H, F, alkyl, and haloalkyl; and R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; R ₁₆ and R ₁₇ are each independently selected from H and alkyl; wherein the compound is other than 6-fluoro-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)-3,4- dihydroisoquinoline-2(1H)-carboxamide. In formula (Ia), and for other aspects, preferably alkyl is C _1- C ₆ alkyl, haloalkyl is C _1- C ₆ haloalkyl, and alkoxy is C _1- C ₆ alkoxy. In one preferred embodiment, Y and Z are each independently selected from CH ₂ , CHMe, CHF, CF ₂ , C(CH ₃ ) ₂ , C(CF ₃ ) ₂ , and are more preferably both CH ₂ . In one preferred embodiment, one of Z and Y is CHMe and the other is CH ₂ . In one preferred embodiment, Y is CHMe and Z is CH ₂ . In one preferred embodiment, Z is CHMe and Y is CH ₂ . In a more preferred embodiment, Z and Y are both CH ₂ . In one embodiment, optional substituents on the A ring are selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl and haloalkyl. More preferably, optional substituents on the A ring are selected from Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl and haloalkyl. In one preferred embodiment, R ₁₁ and R ₁₁ ’ are selected from H and alkyl, and more preferably selected from H and Me, Even more preferably, R ₁₁ and R ₁₁ ’ are both H. In one preferred embodiment, R ₁₂ and R ₁₃ are each independently Me. In one preferred embodiment, the compound of the invention is of formula (Ia'), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic or bicyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, O-aryl, NR ₁₁ R ₁₁ ’, and SO ₂ NR ₁₆ R ₁₇ ; Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each independently selected from H, F, alkyl, and haloalkyl; R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; and R ₁₆ and R ₁₇ are each independently selected from H and alkyl; wherein the compound is other than 6-fluoro-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)-3,4- dihydroisoquinoline-2(1H)-carboxamide. In another preferred embodiment, the compound of the invention is of formula (Ia''), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, O-aryl, NR ₁₁ R ₁₁ ’, and SO ₂ NR ₁₆ R ₁₇ ; Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each independently selected from H, F, alkyl, and haloalkyl; R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; and R ₁₆ and R ₁₇ are each independently selected from H and alkyl; wherein the compound is other than: 6-fluoro-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)-3,4-d ihydroisoquinoline-2(1H)- carboxamide; 5,7-dimethyl-N-(5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)-3 ,4-dihydroisoquinoline-2(1H)- carboxamide; N-(6-ethoxypyridin-2-yl)-7-fluoro-3,4-dihydroisoquinoline-2( 1H)-carboxamide; N-(5-cyanopyridin-2-yl)-5-isopropyl-3,4-dihydroisoquinoline- 2(1H)-carboxamide; and 6-methoxy-N-(6-methoxypyridin-2-yl)-3,4-dihydroisoquinoline- 2(1H)-carboxamide. In one embodiment, the compound of the invention is other than 6-fluoro-N-(5- (trifluoromethyl)-1,3,4-thiadiazol-2-yl)-3,4-dihydroisoquino line-2(1H)-carboxamide. In one embodiment, the compound of the invention is other than 5,7-dimethyl-N-(5- (trifluoromethyl)-1,3,4-thiadiazol-2-yl)-3,4-dihydroisoquino line-2(1H)-carboxamide (or 5,7- dimethyl-N-[5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl]-1,2,3 ,4-tetrahydroisoquinoline-2- carboxamide). In one embodiment, the compound of the invention is other than N-(6-ethoxypyridin-2-yl)-7- fluoro-3,4-dihydroisoquinoline-2(1H)-carboxamide (or N-(6-ethoxypyridin-2-yl)-7-fluoro- 1,2,3,4-tetrahydroisoquinoline-2-carboxamide). In one embodiment, the compound of the invention is other than N-(5-cyanopyridin-2-yl)-5- isopropyl-3,4-dihydroisoquinoline-2(1H)-carboxamide (or N-(5-cyanopyridin-2-yl)-5-(propan- 2-yl)-1,2,3,4-tetrahydroisoquinoline-2-carboxamide). In one embodiment, the compound of the invention is other than 6-methoxy-N-(6- methoxypyridin-2-yl)-3,4-dihydroisoquinoline-2(1H)-carboxami de (or 6-methoxy-N-(6- methoxypyridin-2-yl)-1,2,3,4-tetrahydroisoquinoline-2-carbox amide). In one embodiment, the compound of the invention is other than N-(5-ethyl-1,3,4-thiadiazol- 2-yl)-6-methoxy-3,4-dihydroisoquinoline-2(1H)-carboxamide (or N-(5-ethyl-1,3,4-thiadiazol- 2-yl)-6-methoxy-1,2,3,4-tetrahydroisoquinoline-2-carboxamide ). In one embodiment, the compound of the invention is other than N-(5-isopropylisoxazol-3- yl)-5,7-dimethyl-3,4-dihydroisoquinoline-2(1H)-carboxamide (or 5,7-dimethyl-N-[5-(propan- 2-yl)-1,2-oxazol-3-yl]-1,2,3,4-tetrahydroisoquinoline-2-carb oxamide). In one embodiment, the compound of the invention is other than N-(5-(tert-butyl)-1,3,4- thiadiazol-2-yl)-5,7-difluoro-3,4-dihydroisoquinoline-2(1H)- carboxamide (or N-(5-tert-butyl- 1,3,4-thiadiazol-2-yl)-5,7-difluoro-1,2,3,4-tetrahydroisoqui noline-2-carboxamide). In one embodiment, the compound of the invention is other than N-(5-(tert-butyl)-1,3,4- thiadiazol-2-yl)-7-fluoro-3,4-dihydroisoquinoline-2(1H)-carb oxamide (or N-(5-tert-butyl-1,3,4- thiadiazol-2-yl)-7-fluoro- 1,2,3,4-tetrahydroisoquinoline-2-carboxamide). RING A In one preferred embodiment, the monocyclic aromatic or heteroaromatic ring A is a group selected from benzene pyridine pyridone pyridine N oxide pyridazine pyridazinone pyrimidine, pyrimidone, pyrazine, triazine, triazinone, pyrrole, furan, thiophene, pyrazole, isoxazole, imidazole, oxazole, oxadiazole and thiazole, each of which may be optionally substituted. In one preferred embodiment, the monocyclic aromatic or heteroaromatic ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyridazinone, pyrazine and isoxazole, each of which may be optionally substituted. In one preferred embodiment, ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyridazinone, pyrazine, and isoxazole, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, phenyl, SO ₂ -alkyl, CO ₂ -alkyl, thienyl, halo- substituted pyridinyl, and C ₁ -C ₆ haloalkyl. Preferably, the one or more substituents are selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, phenyl, SO ₂ -alkyl, CO ₂ -alkyl, thienyl, halo-substituted pyridinyl, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyridazinone, pyrazine, and isoxazole, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In some instances, ring A can exist in more than one tautomeric form. By way of illustration, where the heteroaromatic ring is substituted by an OH group, ring A can exist as two possible tautomers as shown below: The 2-pyridone tautomer is believed to be the predominant solid state form. In solution, the energy difference between the two tautomeric forms is understood to be very small and is dependent on the polarity of the solvent. The skilled person would appreciate that other hydroxy substituted N-containing heteroaromatic groups (e.g. pyrimidine, other pyridine regioisomers) can be similarly represented in tautomeric form as shown above. The term “heteroaromatic” as used herein encompasses all tautomeric forms of the compounds. In one preferred embodiment, the monocyclic aromatic or heteroaromatic ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyridazine, pyradazinone, pyrimidine, pyrimidone, pyrazine, triazine, triazinone, pyrrole, furan, thiophene, pyrazole, isoxazole, imidazole, oxazole, oxadiazole and thiazole, each of which is optionally substituted. In one preferred embodiment, the monocyclic aromatic or heteroaromatic ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyrazine and isoxazole, each of which is optionally substituted. In one preferred embodiment, A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl. In one preferred embodiment, A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkyl, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl. In one preferred embodiment, ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyrazine and isoxazole, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, phenyl, SO ₂ -alkyl, CO ₂ -alkyl, thienyl, halo-substituted pyridinyl, and C ₁ -C ₆ haloalkyl. In another preferred embodiment, ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyrazine and isoxazole, each of which is optionally substituted with one or more substituents selected from Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, phenyl, SO ₂ -alkyl, CO ₂ -alkyl, thienyl, halo- substituted pyridinyl, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyrazine, and isoxazole, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a group selected from benzene, pyridine, pyridone, pyridine N-oxide, pyrimidine, pyrimidone, pyridazine, pyrazine, and isoxazole, each of which is optionally substituted with one or more substituents selected from Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a benzene group which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a benzene group which is substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In another preferred embodiment, ring A is a benzene group which is optionally substituted with one or more substituents selected from Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a benzene group which is substituted with one or more substituents selected from Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ - alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a pyridine group which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a pyridone group which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, SO ₂ -alkyl, CO ₂ -alkyl, l, and C ₁ -C ₆ haloalkyl. In one preferred embodiment, ring A is a 9- or 10-membered bicyclic heteroaromatic ring containing 1 to 4 nitrogen atoms, more preferably 1 to 3 nitrogen atoms. Preferably, the 9- or 10-membered bicyclic heteroaromatic ring containing 1 to 4 nitrogen atoms is selected from a triazolopyridine and an imidazopyridine, each of which is optionally substituted. More f bl th 9 10 b d bi li h t ti i t i i 1 t 4 it atoms is selected from [1,2,4]triazolo[4,3-a]pyridine, [1,2,4]triazolo[1,5-a]pyridine, imidazo[1,5-a]pyridine and imidazo[1,2-a]pyridine, each of which is optionally substituted. Preferably, the 9- or 10-membered bicyclic heteroaromatic ring is optionally substituted by one or more substituents selected from halo, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, phenyl, SO ₂ -alkyl, CO ₂ -alkyl, thienyl, halo-substituted pyridinyl, and C ₁ -C ₆ haloalkyl. More preferably, the 9- or 10-membered bicyclic heteroaromatic ring is optionally substituted by one or more substituents selected from Me, Cl, F, CN, MeO, NH ₂ , OH, CO ₂ Me, SO ₂ Me, thienyl and fluoropyridinyl. Preferably, ring A is as defined below, where the wavy lines denote attachment to the ring containing N, Z and Y: In one preferred embodiment, ring A is selected from:

wherein R ₆ , R ₇ , R ₈ , and R ₉ are each independently selected from H, F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, CO ₂ -alkyl, SO ₂ -alkyl, NR ₁₁ R ₁₁ ’, optionally substituted heteroaryl, OH, C ₁ -C ₆ alkyl, phenyl, and C ₁ -C ₆ haloalkyl, and R ₁₄ is H or alkyl. In one preferred embodiment, ring A is a group selected from (i)-(xxxiv) above, wherein R ₆ , R ₇ , R ₈ , and R ₉ are each independently selected from H, F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, CO ₂ - alkyl, SO ₂ -alkyl, NR ₁₁ R ₁₁ ’, OH, optionally substituted heteroaryl, phenyl, and C ₁ -C ₆ haloalkyl, and R ₁₄ is H or alkyl. In one preferred embodiment, ring A is a group selected from (i)-(xxxiv) above, wherein R ₆ , R ₇ , R ₈ , and R ₉ are each independently selected from H, F, Cl, Br, I, CN, CO ₂ -alkyl, SO ₂ - alkyl, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, optionally substituted heteroaryl, phenyl, and C ₁ -C ₆ haloalkyl, and R ₁₄ is H or alkyl. In one preferred embodiment, ring A is a group selected from (i)-(xxxiv) above, wherein R ₆ , R ₇ , R ₈ , and R ₉ are each independently selected from H, F, Cl, Br, I, CN, CO ₂ -alkyl, SO ₂ - alkyl, NR ₁₁ R ₁₁ ’, OH, optionally substituted heteroaryl, phenyl, and C ₁ -C ₆ haloalkyl, and R ₁₄ is H or alkyl. In one preferred embodiment, A is selected from a group A(i)-A(xxxiii). In one preferred embodiment, R ₁₄ is H or Me, more preferably, H. In one preferred embodiment, R ₆ , R ₇ , R ₈ , and R ₉ are each independently selected from H, F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, heteroaryl, OH, C ₁ -C ₆ alkyl, phenyl, and C ₁ -C ₆ h l lk l d R i H lk l In one preferred embodiment, R ₆ , R ₇ , R ₈ , and R ₉ are each independently selected from H, F, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, phenyl, and C ₁ -C ₆ haloalkyl, and R ₁₄ is H or alkyl. In one preferred embodiment, R ₆ , R ₇ , R ₈ , and R ₉ are each independently selected from H, Cl, Br, I, CN, C ₁ -C ₆ alkoxy, NR ₁₁ R ₁₁ ’, OH, C ₁ -C ₆ alkyl, phenyl, and C ₁ -C ₆ haloalkyl, and R ₁₄ is H or alkyl. In one preferred embodiment, ring A is selected from the following groups: wherein R ₆ -R ₉ and R ₁₄ are as defined above. In one preferred embodiment, ring A is a group A-(i), A(ii) or A-(vii), and R ₆ -R ₉ are each independently selected from H, F, Cl, CN, NH ₂ , OMe, CH ₃ and CF ₃ . In one preferred embodiment, R ₆ , R ₈ and R ₉ are H, and R ₇ is selected from Cl, F and CN. In one preferred embodiment: ring A is a group A-(i); R ₆ is selected from H, F, Cl, CN, OMe and CH ₃ ; R ₇ is selected from H, NH ₂ , F, Cl, CN, OMe, CH ₃ , and CF ₃ ; R ₈ is selected from H, F, Cl, CN, OMe, CH ₃ , and CF ₃ ; and R ₉ is selected from H, F, Cl, CN, CH ₃ and CF ₃ . Preferably, where A is a group A-(i), R ₇ is selected from NH ₂ , F, Cl, CN, OMe, CH ₃ , and CF ₃ , and is more preferably selected from Cl, F and CN. In one preferred embodiment, where A is a group A-(i), R ₇ is selected from NH ₂ , Cl, CN, OMe, CH ₃ , and CF ₃ , and is more preferably selected from Cl and CN. Preferably, where A is a group A-(i), R ₆ , R ₈ and R ₉ are all H, and R ₇ is selected from Cl, F and CN. More preferably, where A is a group A-(i), R ₆ , R ₈ and R ₉ are all H, and R ₇ is selected from Cl and CN In one preferred embodiment: ring A is a group A-(xi); R ₆ is selected from H, F, Cl, CN, OMe and CH ₃ ; R ₉ is selected from H, F, Cl, CN, OMe, CH ₃ and CF ₃ ; and R ₁₄ is selected from H and Me. Preferably, where ring A is a group A-(xi), R ₆ , R ₉ and R ₁₄ are all H. In one preferred embodiment: ring A is a group A-(ii); R ₆ and R ₉ are H; and R ₇ is selected from Cl, F and CN, more preferably F. In one preferred embodiment: ring A is a group A-(vii); R ₈ and R ₉ are H; and R ₆ is selected from Cl, F and CN, more preferably F. In one preferred embodiment, ring A is a 9- or 10-membered bicyclic heteroaromatic ring containing 1 to 4 nitrogen atoms selected from groups A(xxi) to A-(xxviii). RING B In one preferred embodiment, ring B is an optionally substituted monocyclic heteroaromatic group containing at least one nitrogen atom. In one preferred embodiment, ring B is of formula: B-(i) wherein where n is 0 or 1 and X ₁ -X ₅ form a 5- or 6-membered heteroaromatic group containing at least one nitrogen atom, said heteroaromatic group being optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, aryl, heteroaryl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ . In one preferred embodiment, ring B is of formula B-(i), n is 0 or 1, and X ₁ -X ₅ form a 5- or 6- membered heteroaromatic group containing at least one nitrogen atom, said heteroaromatic group being optionally substituted by one or more substituents selected from halo, CN, alkoxy, haloalkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ , more preferably, halo, CN, haloalkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ . In one preferred embodiment, n is 1, and X ₁ -X ₅ form a 6-membered heteroaromatic group selected from pyridin-2-yl, pyridin-3-yl, pyridin-4-yl, pyrazin-2-yl, pyrimidin-2-yl, pyrimidin-4- yl and pyrimidin-5-yl, each of which is optionally substituted by one or more substituents selected from halo, CN, alkoxy, alkyl, haloalkyl, aryl, heteroaryl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, CN, alkoxy, alkyl and haloalkyl. In one preferred embodiment, n is 1, and X ₁ -X ₅ form a 6-membered heteroaromatic group selected from pyridin-2-yl, pyridin-3-yl, pyridin-4-yl, pyrazin-2-yl, pyrimidin-2-yl, pyrimidin-4- yl and pyrimidin-5-yl, each of which is optionally substituted by one or more substituents selected from halo, CN, alkoxy, haloalkyl, and O-aryl, more preferably, halo, CN, alkoxy and haloalkyl. In one preferred embodiment, R ₁₆ and R ₁₇ are each independently selected from H and Me. In one preferred embodiment, ring B is of formula: wherein: X ₁ is N or CR ₁ ; X ₂ is N or CR ₂ ; X ₃ is N or CR ₃ ; X ₄ is N or CR ₄ ; X ₅ is N or CR ₅ ; wherein at least one of X ₁ to X ₅ is N; and R ₁ -R ₅ are each independently selected from H, halo, CN, alkoxy, alkyl, haloalkyl, haloalkoxy, aryl, heteroaryl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, CN, alkoxy, alkyl and haloalkyl. In another preferred embodiment, ring B is of formula B-(ii), where X ₁ -X ₅ are as defined above, and R ₁ -R ₅ are each independently selected from H, halo, CN, alkoxy, haloalkyl, haloalkoxy, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, alkoxy, CN, and haloalkyl. In one preferred embodiment, X ₁ is N, X ₂ is CR ₂ , X ₃ is R ₃ , X ₄ is CR ₄ and X ₅ is CR ₅ . In one preferred embodiment, X ₁ is CR ₁ , X ₂ is N, X ₃ is CR ₃ , X ₄ is CR ₄ and X ₅ is CR ₅ . In one preferred embodiment, X ₁ is CR ₁ , X ₂ is CR ₂ , X ₃ is N, X ₄ is CR ₄ and X ₅ is CR ₅ . In one preferred embodiment, X ₁ is N, X ₂ is CR ₂ , X ₃ is CR ₃ , X ₄ is N and X ₅ is CR ₅ . In one preferred embodiment, X ₁ is N, X ₂ is CR ₂ , X ₃ is CR ₃ , X ₄ is CR ₄ and X ₅ is N. In one preferred embodiment, X ₁ is CR ₁ , X ₂ is N, X ₃ is CR ₃ , X ₄ is N and X ₅ is CR ₅ ; In one preferred embodiment, X ₁ is N, X ₂ is CR ₂ , X ₃ is N, X ₄ is CR ₄ and X ₅ is CR ₅ ; In one preferred embodiment, X ₁ is N, X ₂ is N, X ₃ is CR ₃ , X ₄ is CR ₄ and X ₅ is CR ₅ ; and In one preferred embodiment, X ₁ is CR ₁ , X ₂ is N, X ₃ is N, X ₄ is CR ₄ and X ₅ is CR ₅ . In one preferred embodiment, X ₁ is N, X ₂ is CR ₂ , X ₃ is N, X ₄ is CR ₄ and X ₅ is N. In one preferred embodiment, ring B is of formula: wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from H, halo, haloalkyl, alkyl, alkoxy, CN, aryl, heteroaryl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ , f bl H h l CN lk lk l d h l lk l In another preferred embodiment, ring B is of formula B-(iii) above, wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from H, halo, haloalkyl, alkoxy, CN, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, CN, alkoxy and haloalkyl. In one preferred embodiment, R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from H, halo and haloalkyl, and more preferably selected from H, Cl, F and CF ₃ . In one preferred embodiment, R ₁ and R ₄ are both H, and R ₂ and R ₃ are each independently selected from halo and haloalkyl, more preferably selected from Cl, F and CF ₃ . In one preferred embodiment, R ₁ and R ₄ are both H, R ₂ is Cl and R ₃ is Cl or CF ₃ . In one preferred embodiment, n is 0, and X ₁ -X ₄ form a 5-membered heteroaromatic group containing at least one nitrogen atom, said heteroaromatic group being optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, aryl, heteroaryl, CO ₂ -alkyl, cycloalkyl, heterocycloalkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ . In one preferred embodiment, n is 0, and X ₁ -X ₄ form a 5-membered heteroaromatic group containing at least one nitrogen atom, said heteroaromatic group being optionally substituted by one or more substituents selected from halo, CN, alkoxy, haloalkyl, cycloalkyl, heterocycloalkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ . In one preferred embodiment, wherein n is 0, and X ₁ -X ₄ form a 5-membered heteroaromatic group selected from oxadiazoyl, thiadiazolyl, imidazolyl, pyrrolyl, pyrazolyl, diazolyl, triazolyl, isoxazolyl, isothiazolyl, tetrazolyl, oxazolyl, and thiazolyl, and wherein said heteroaromatic group is optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, aryl, heteroaryl, CO ₂ -alkyl, cycloalkyl, heterocycloalkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ . In one preferred embodiment, n is 0, and X ₁ -X ₄ form a 5-membered heteroaromatic group selected from oxadiazoyl, thiadiazolyl, imidazolyl, pyrrolyl, pyrazolyl, diazolyl, triazolyl, isoxazolyl, isothiazolyl, tetrazolyl, oxazolyl, and thiazolyl, and wherein said heteroaromatic group is optionally substituted by one or more substituents selected from halo, CN, alkoxy, haloalkyl, cycloalkyl, heterocycloalkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ . In one preferred embodiment, ring B is of formula: B-(iv) wherein: X ₁ -X ₄ form a heteroaromatic group containing at least one nitrogen atom, wherein: X ₁ is N or CR ₁ ; X ₂ is N or CR ₂ ; X ₃ is N or CR ₃ ; X ₄ is selected from NR ₁₅ , O and S, where R ₁₅ is H, alkyl or haloalkyl; and R ₁ -R ₃ are each independently selected from H, halo, CN, alkoxy, alkyl, haloalkyl, aryl, heteroaryl, heterocycloalkyl, cycloalkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, CN, alkoxy, alkyl, cyclopropyl and tetrahydropyranyl and haloalkyl. In one preferred embodiment, ring B is of formula B-(iv) above, wherein R ₁ -R ₃ are each independently selected from H, halo, CN, alkoxy, haloalkyl, heterocycloalkyl, cycloalkyl, O- aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, CN, alkoxy, cyclopropyl and tetrahydropyranyl and haloalkyl. In one preferred embodiment, R ₁₅ is H or Me, more preferably, H. In one preferred embodiment: X ₁ is N, X ₂ is N, X ₃ is CR ³ and X ⁴ is S X ₁ is N, X ₂ is N, X ₃ is CR ₃ and X ⁴ is O; X ₁ is N, X ₂ is CR ₂ , X ₃ is N and X ⁴ is O; X ₁ is CR ₁ , X ₂ is N, X ₃ is CR ³ and X ⁴ is S; X ₁ is N, X ₂ is CR ₂ , X ₃ is CR ³ and X ⁴ is S; or In one preferred embodiment, ring B is of formula: wherein R ₃ is H, halo or haloalkyl, more preferably CF ₃ . In one preferred embodiment, ring B is of formula: B-(vi) wherein: X ₁ -X ₄ form a heteroaromatic group containing at least one nitrogen atom, wherein: X ₁ is N or CR ₁ ; X ₂ is N or CR ₂ ; X ₃ is selected from NR ₁₅ , O and S, where R ₁₅ is H, alkyl or haloalkyl; X ₄ is N or CR ₄ ; and R ₁ , R ₂ and R ₄ are each independently selected from H, halo, CN, alkoxy, alkyl, haloalkyl, aryl, heteroaryl, CO ₂ -alkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, CN, alkoxy, alkyl, CO ₂ Me and haloalky. In one preferred embodiment, ring B is of formula B-(vi), wherein R ₁ , R ₂ and R ₄ are each independently selected from H, halo, CN, alkoxy, haloalkyl, CO ₂ -alkyl, O-aryl, NHCOR ₁₂ , NHSO ₂ R ₁₃ , and SO ₂ NR ₁₆ R ₁₇ , more preferably, H, halo, CN, alkoxy, and haloalkyl. In one preferred embodiment: X ₁ is CR ₁ , X ₂ is N, X ₃ is O and X ₄ is N; X ₁ is N, X ₂ is CR ₂ , X ₃ is O and X ₄ is N; X ₁ is CR ₁ , X ₂ is CR ₂ , X ₃ is NR ₁₅ and X ₄ is N; or X ₁ is CR ₁ , X ₂ is CR ₂ , X ₃ is O and X ₄ is N. In one preferred embodiment, ring B is of formula: B-(vii) wherein R ₁ and R ₂ are each independently selected from H, halo and haloalkyl. In one preferred embodiment, R ₁ is H and R ₂ is haloalkyl, more preferably CF ₃ . In one preferred embodiment, ring B is an optionally substituted bicyclic heteroaromatic group containing at least one nitrogen atom, preferably, an optionally substituted 9- or 10- membered bicyclic heteroaromatic group containing at least one nitrogen atom. In one preferred embodiment, ring B is a bicyclic heteroaromatic group selected from benzimidazolyl, pyrazolopyridinyl, indolyl, indolizinyl, isoindolyl, indazolyl, quinolinyl, isoquinolinyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl and naphthyridinyl, and wherein said bicyclic heteroaromatic group is optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, aryl, heteroaryl and O-aryl. In one preferred embodiment, ring B is of formula: wherein X ₂ and X ₃ are both C, one, two or three of X ₁ , X ₄ , X ₅ -X ₉ are N and the rest are selected from C-H, C-alkyl and C-haloalkyl. In one preferred embodiment, X ₉ is N, X ₂ and X ₃ are both C, X ₁ , X ₄ , X ₅ X ₆ and X ₇ are CH, and X ₈ is C-haloalkyl more preferably, CF ₃ . In one preferred embodiment, ring B is a bicyclic heteroaromatic group selected from the following: wherein: X ₂ and X ₃ are both C; X ₇ is selected from O, S and NR ₁₅ , where R ₁₅ is H, alkyl or haloalkyl; and one, two or three of X ₁ , X ₄ , X ₅ , X ₆ and X ₈ are N and the rest are selected from C-H, C-alkyl and C-haloalkyl. In one preferred embodiment, ring B is a heteroaromatic group of formula: wherein: X ₅ , X ₈ are N, X ₂ and X ₃ are both C, X ₁ , X ₄ , X ₅ and X ₆ are CH, and X ₇ is N-haloalkyl, more preferably N-CHF ₂ ; or X ₆ , X ₈ are N, X ₂ and X ₃ are both C, X ₁ , X ₄ and X ₅ are CH, and X ₇ is O. In one preferred embodiment, ring B is a bicyclic heteroaromatic group selected from the following: wherein: X ₂ and X ₃ are both C; X ₇ is selected from O, S and NR ₁₅ , where R ₁₅ is H, alkyl or haloalkyl; and one, two or three of X ₁ , X ₄ , X ₅ , X ₆ and X ₈ are N and the rest are selected from C-H, C-alkyl and C-haloalkyl.

In another aspect, the invention relates to a compound selected from compounds (1), (2), (3), (11), (14), (15), (17), (18), (20), (21), (22), (23), (24), (25), (26), (27), (28) and (29) as described above, and pharmaceutically acceptable salts and solvates thereof. THERAPEUTIC APPLICATIONS A further aspect of the invention relates to compounds as described herein for use in medicine. The compounds have particular use in the field of oncology, immuno-oncology, and immunology as described in more detail below. In a preferred embodiment, the compound of the invention modulates GPR65, and more preferably inhibits GPR65 signalling. Yet another aspect of the invention relates to compounds as described herein for use as a medicament. One aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic or bicyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, alkyl, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, CO ₂ -alkyl, O-aryl, NR ₁₁ R ₁₁ ’, CONR ₁₆ R ₁₇ and SO ₂ NR ₁₆ R ₁₇ ; Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each independently selected from H, F, alkyl, and haloalkyl; R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; R ₁₆ and R ₁₇ are each independently selected from H and alkyl; for use as a medicament. Another aspect of the invention relates to a compound of formula (I'), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic or bicyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, O-aryl, NR ₁₁ R ₁₁ ’, and SO ₂ NR ₁₆ R ₁₇ ; Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each independently selected from H, F, alkyl, and haloalkyl; R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; R ₁₆ and R ₁₇ are each independently selected from H and alkyl; for use as a medicament. Another aspect of the invention relates to a compound of formula (I''), or a pharmaceutically acceptable salt or solvate thereof, wherein: ring A is a 5- or 6-membered monocyclic aromatic or heteroaromatic ring, or a 9- or 10-membered bicyclic aromatic or heteroaromatic ring, each of which is optionally substituted with one or more substituents selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, SO ₂ -alkyl, CO ₂ -alkyl, alkyl, haloalkyl, aralkyl, aryl, and heteroaryl, and wherein said aryl and heteroaryl substituents are in turn optionally substituted with one or more substituents each independently selected from F, Cl, Br, I, CN, alkoxy, NR ₁₁ R ₁₁ ’, OH, alkyl, haloalkyl, and aralkyl; ring B is a monocyclic heteroaromatic group containing at least one nitrogen atom, which is optionally substituted by one or more substituents selected from halo, CN, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocycloalkyl, O-aryl, NR ₁₁ R ₁₁ ’ and SO ₂ NR ₁₆ R ₁₇ ; Y and Z are each independently CR ₁₀ R ₁₀ ’, wherein R ₁₀ and R ₁₀ ’ are each independently selected from H, F, alkyl, and haloalkyl; R ₁₁ and R ₁₁ ’ are each independently selected from H, alkyl, haloalkyl, COR ₁₂ , and SO ₂ R ₁₃ , wherein R ₁₂ and R ₁₃ are each independently alkyl; and R ₁₆ and R ₁₇ are each independently selected from H and alkyl; for use as a medicament. Preferred definitions for ring A, ring B, Y and Z are as set out above for compounds of formula (Ia) and (Ia') and (Ia''). In formula (I), (I') and (I''), preferably alkyl is C _1- C ₆ alkyl, haloalkyl is C _1- C ₆ haloalkyl, and alkoxy is C _1- C ₆ alkoxy. Preferably, the compounds of formula (I), (I') and (I'') are for use in treating or preventing a disease or disorder selected from a proliferative disorder, an autoimmune disorder, asthma, chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). One preferred embodiment of the invention relates to compounds as described herein for use in treating or preventing a disorder selected from a proliferative disorder and an immune disorder. Another preferred embodiment of the invention relates to compounds as described herein for use in treating or preventing asthma and/or chronic obstructive pulmonary disease (COPD). GPR65 variant/SNP (rs6574978) has been shown to be associated with asthma/COPD syndrome with almost GWAS significant p value (1.18x10e-7) (Hardin 2014). Furthermore, GPR65 activation by pH (pH is low/acidic in asthmatic lungs) promotes eosinophil viability in a cAMP-dependent manner, contributing to disease progression/exacerbation. It is further known that GPR65 KO mice have attenuated asthma symptoms (Kottyan 2009). Another aspect of the invention relates to compounds as described herein for use in treating or preventing acute respiratory distress syndrome (ARDS). GPR65 has been shown to be One aspect of the invention relates to a compound as described herein for use in treating a proliferative disorder. Preferably, the proliferative disorder is a cancer or leukemia. In one preferred embodiment, the cancer is a solid tumour and/or metastases thereof. In another preferred embodiment, the cancer is selected from melanoma, renal cell carcinoma (RCC), gastric cancer, acute myeloid leukaemia (AML), pancreatic adenocarcinoma, triple negative breast cancer (TNBC), colorectal cancer, head and neck cancer, colorectal adenocarcinoma, lung cancer, sarcoma, ovarian cancer, and gliomas, preferably glioblastoma (GBM). Without wishing to be bound by theory, it is understood that GPR65 modulators are capable of preventing the increase in cytoplasmic cAMP in tumour-associated macrophages (TAMs), natural killer (NK) cells and subsets of T cells that would typically result from their exposure to the acidic tumour microenvironment and concomitant GPR65 activation. This reduction in the level of cytoplasmic cAMP in turn reduces the levels of ICER pro- inflammatory mediators such as CXCL10 and and TNFα, preventing the polarization of TAMs and alteration of other immune cells that are associated with a non-inflammatory and tumour-permissive environment. Therefore, GPR65 modulators are expected to result in an increase in the visibility of the tumour to the immune system leading to increased immune- mediated tumour clearance. This suggests that modulation of GPR65 activity could be an effective treatment for cancer as stand-alone therapy or in combination with cancer immunotherapies (vaccines, agents that promote T cell mediated immune responses) or in patients that do not respond to immunomodulatory approaches such as PD1/PDL-1 blockade. Another aspect of the invention relates to a compound as described herein for use in treating an immune disorder, preferably an autoimmune disease. In one embodiment, the autoimmune disease is selected from psoriasis, psoriatic arthritis, rheumatoid arthritis (RA), multiple sclerosis (MS), systemic lupus erythematosus (SLE), autoimmune thyroiditis (Hashimoto's thyroiditis), Graves' disease, uveitis (including intermediate uveitis), ulcerative colitis, Crohn’s disease, autoimmune uveoretinitis, systemic vasculitis, polymyositis-dermatomyositis, systemic sclerosis (scleroderma), Sjogren's Syndrome, ankylosing spondylitis and related spondyloarthropathies, sarcoidosis, autoimmune hemolytic anemia, immunological platelet disorders, autoimmune polyendocrinopathies and autoimmune myocarditis, type I diabetes and atopic dermatitis In a particularly preferred embodiment, the autoimmune disease is selected from psoriasis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, and multiple sclerosis (MS). Without wishing to be bound by theory, it is understood that GPR65 modulators will prevent the upregulation of ICER in CD4+ T cells. This, in turn, is expected to prevent the ICER- associated suppression of IL‐2 that biases CD4+ T cells toward the inflammatory Th17 phenotype associated with increased pathogenicity in the context of autoimmune disease. This is supported by the fact that mutations in the GPR65 locus are associated with several autoimmune diseases, such as multiple sclerosis, ankylosing spondylitis, inflammatory bowel disease, and Crohn’s disease (Gaublomme, 2015). This suggests that modulation of GPR65 activity could be an effective treatment for autoimmune diseases. Another aspect relates to a compound as described herein for use in treating or preventing a disorder caused by, associated with or accompanied by abnormal activity against GPR65. Another aspect relates to a compound as described herein for use in treating or preventing a GPR65-associated disease or disorder. Another aspect of the invention relates to a method of treating a disorder as described above comprising administering a compound as described herein to a subject. Another aspect of the invention relates to a method of treating a GPR65-associated disease or disorder in a subject. The method according to this aspect of the present invention is effected by administering to a subject in need thereof a therapeutically effective amount of a compound of the present invention, as described hereinabove, either per se, or, more preferably, as a part of a pharmaceutical composition, mixed with, for example, a pharmaceutically acceptable carrier, as is detailed hereinafter. Yet another aspect of the invention relates to a method of treating a subject having a disease state alleviated by modulation of GPR65 wherein the method comprises administering to the subject a therapeutically effective amount of a compound according to the invention. Another aspect relates to a method of treating a disease state alleviated by modulation of GPR65, wherein the method comprises administering to a subject a therapeutically effective amount of a compound according to the invention. Preferably, the subject is a mammal, more preferably a human. The term “method” refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts. Herein, the term “treating” includes abrogating, substantially inhibiting, slowing or reversing the progression of a disease or disorder, substantially ameliorating clinical symptoms of a disease or disorder or substantially preventing the appearance of clinical symptoms of a disease or disorder. Herein, the term “preventing” refers to a method for barring an organism from acquiring a disorder or disease in the first place. The term “therapeutically effective amount” refers to that amount of the compound being administered which will relieve to some extent one or more of the symptoms of the disease or disorder being treated. For any compound used in this invention, a therapeutically effective amount, also referred to herein as a therapeutically effective dose, can be estimated initially from cell culture assays. For example, a dose can be formulated in animal models to achieve a circulating concentration range that includes the IC ₅₀ or the IC ₁₀₀ as determined in cell culture. Such information can be used to more accurately determine useful doses in humans. Initial dosages can also be estimated from in vivo data. Using these initial guidelines one of ordinary skill in the art could determine an effective dosage in humans. Moreover, toxicity and therapeutic efficacy of the compounds described herein can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., by determining the LD ₅₀ and the ED ₅₀ . The dose ratio between toxic and therapeutic effect is the therapeutic index and can be expressed as the ratio between LD ₅₀ and ED ₅₀ . Compounds which exhibit high therapeutic indices are preferred. The data obtained from these cell cultures assays and animal studies can be used in formulating a dosage range that is not toxic for use in human. The dosage of such compounds lies preferably within a range of circulating concentrations that include the ED ₅₀ with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized. The exact formulation, route of administration and dosage can be chosen by the individual physician in view of the patient's condition. (see, e.g., Fingl et al, 1975, The Pharmacological Basis of Therapeutics, chapter 1, page 1). Dosage amount and interval may be adjusted individually to provide plasma levels of the active compound which are sufficient to maintain therapeutic effect. Usual patient dosages for oral administration range from about 50-2000 mg /day, commonly from about 100-1000 mg/ day, preferably from about 150-700 mg/day and most preferably from about 250-500 mg/day, or from 50-100 mg/day. Preferably, therapeutically effective serum levels will be achieved by administering multiple doses each day. In cases of local administration or selective uptake, the effective local concentration of the drug may not be related to plasma concentration. One skilled in the art will be able to optimize therapeutically effective local dosages without undue experimentation. As used herein, “GPR65-related disease or disorder” refers to a disease or disorder characterized by inappropriate GPR65 activity. Inappropriate GPR65 activity refers to either an increase or decrease in GPR65 activity as measured by enzyme or cellular assays, for example, compared to the activity in a healthy subject. Inappropriate activity could also be due to overexpression of GPR65 in diseased tissue compared with healthy adjacent tissue. Preferred diseases or disorders that the compounds described herein may be useful in treating or preventing include proliferative disorders and immune disorders as described hereinbefore, as well as asthma and chronic obstructive pulmonary disease. The present invention further provides for the use of compounds as defined herein in the preparation of a medicament for the treatment of a disease where it is desirable to modulate GPR65. Such diseases include proliferative disorders and immune disorders as described hereinbefore, as well as asthma, chronic obstructive pulmonary disease and acute respiratory distress syndrome. As used herein the phrase “preparation of a medicament” includes the use of the components of the invention directly as the medicament in addition to their use in any stage of the preparation of such a medicament. In one preferred embodiment, the compound prevents the increase in cytoplasmic cAMP levels expected following GPR65 activation at acidic pH. This prevention of cAMP accumulation is expected in turn to prevent the undesirable downstream signalling through ICER, as described in the accompanying examples section. The “Human GPR65 cyclic adenosine monophosphate (cAMP) Homogeneous Time Resolved Fluorescence (HTRF) antagonist assay”, or simply “cAMP assay”, as described below, can be used to measure the potency of GPR65 modulators, which is expressed as the concentration of compound required to reduce the increase in cAMP concentration upon GPR65 activation by 50% (i.e. an IC ₅₀ ). In one preferred embodiment, the compound exhibits an IC ₅₀ value in the cAMP assay of less than about 25 µM. More preferably, the compound exhibits an IC ₅₀ value in the cAMP assay of less than about 10 µM, more preferably, less than about 5 µM, even more preferably, less than about 1 µM, even more preferably, less than about 0.1 µM. In another preferred embodiment, the compound exhibits an hGPR65 IC ₅₀ value of less than < 5 μM, more preferably less than < 500 nM in the aforementioned assay. In one preferred embodiment, the compound according to the invention, or for use according to the invention is selected from the following:

Preferred compounds according to the invention, or for use according to the invention are alternatively described below:

and pharmaceutically acceptable salts and solvates thereof. In one particularly preferred embodiment, the compound according to the invention, or for use according to the invention is selected from the following: 1-4, 9-11, 15-17, 19, 21, and 23-29, more preferably, 1-4, 10-11, 15-17, 19, 21, 23-20. PHARMACEUTICAL COMPOSITIONS A further aspect of the invention relates to pharmaceutical compositions comprising a compound, or a pharmaceutically acceptable salt or solvate thereof, as defined herein, and a pharmaceutically acceptable diluent, excipient, or carrier. For use according to the present invention, the compounds or physiologically acceptable salt, ester or other physiologically functional derivative thereof, described herein, may be presented as a pharmaceutical formulation, comprising the compounds or physiologically acceptable salt, ester or other physiologically functional derivative thereof, together with one or more pharmaceutically acceptable carriers, diluents or excipients therefor and optionally other therapeutic and/or prophylactic ingredients. The carrier(s) must be acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. The pharmaceutical compositions may be for human or animal usage in human and veterinary medicine. Examples of such suitable excipients for the various different forms of pharmaceutical compositions described herein may be found in the “Handbook of Pharmaceutical Excipients, 2 ^nd Edition, (1994), Edited by A Wade and PJ Weller. The carrier, or, if more than one be present, each of the carriers, must be acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient. Acceptable carriers or diluents for therapeutic use are well known in the pharmaceutical art, and are described, for example, in Remington's Pharmaceutical Sciences, Mack Publishing Co. (A. R. Gennaro edit.1985). Examples of suitable carriers include lactose, starch, glucose, methyl cellulose, magnesium stearate, mannitol, sorbitol and the like. Examples of suitable diluents include ethanol, glycerol and water. The choice of pharmaceutical carrier, excipient or diluent can be selected with regard to the intended route of administration and standard pharmaceutical practice. The pharmaceutical compositions may comprise as, or in addition to, the carrier, excipient or diluent any suitable binder(s), lubricant(s), suspending agent(s), coating agent(s), solubilising agent(s), b ff ( ) fl i t( ) f ti t( ) thi k ( ) ti ( ) (including anti-oxidants) and the like, and substances included for the purpose of rendering the formulation isotonic with the blood of the intended recipient. Examples of suitable binders include starch, gelatin, natural sugars such as glucose, anhydrous lactose, free-flow lactose, beta-lactose, corn sweeteners, natural and synthetic gums, such as acacia, tragacanth or sodium alginate, carboxymethyl cellulose and polyethylene glycol. Examples of suitable lubricants include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. Preservatives, stabilizers, dyes and even flavoring agents may be provided in the pharmaceutical composition. Examples of preservatives include sodium benzoate, sorbic acid and esters of p-hydroxybenzoic acid. Antioxidants and suspending agents may be also used. Pharmaceutical formulations include those suitable for oral, topical (including dermal, buccal and sublingual), rectal or parenteral (including subcutaneous, intradermal, intramuscular and intravenous), nasal and pulmonary administration e.g., by inhalation. The formulation may, where appropriate, be conveniently presented in discrete dosage units and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing into association an active compound with liquid carriers or finely divided solid carriers or both and then, if necessary, shaping the product into the desired formulation. Pharmaceutical formulations suitable for oral administration wherein the carrier is a solid are most preferably presented as unit dose formulations such as boluses, capsules or tablets each containing a predetermined amount of active compound. A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine an active compound in a free-flowing form such as a powder or granules optionally mixed with a binder, lubricant, inert diluent, lubricating agent, surface-active agent or dispersing agent. Moulded tablets may be made by moulding an active compound with an inert liquid diluent. Tablets may be optionally coated and, if uncoated, may optionally be scored. Capsules may be prepared by filling an active compound, either alone or in admixture with one or more accessory ingredients, into the capsule shells and then sealing them in the usual manner. Cachets are analogous to capsules wherein an active compound together with any accessory ingredient(s) is sealed in a rice paper envelope. An active compound may also be formulated as dispersible granules, which may for example be suspended in water before administration, or sprinkled on food. The granules may be packaged, e.g., in a sachet. Formulations suitable for oral administration wherein the carrier is a liquid may be presented as a solution or a suspension in an aqueous or non-aqueous liquid, or as an oil-in-water liquid emulsion. Formulations for oral administration include controlled release dosage forms, e.g., tablets wherein an active compound is formulated in an appropriate release - controlling matrix, or is coated with a suitable release - controlling film. Such formulations may be particularly convenient for prophylactic use. Pharmaceutical formulations suitable for rectal administration wherein the carrier is a solid are most preferably presented as unit dose suppositories. Suitable carriers include cocoa butter and other materials commonly used in the art. The suppositories may be conveniently formed by admixture of an active compound with the softened or melted carrier(s) followed by chilling and shaping in moulds. Pharmaceutical formulations suitable for parenteral administration include sterile solutions or suspensions of an active compound in aqueous or oleaginous vehicles. Injectable preparations may be adapted for bolus injection or continuous infusion. Such preparations are conveniently presented in unit dose or multi-dose containers which are sealed after introduction of the formulation until required for use. Alternatively, an active compound may be in powder form which is constituted with a suitable vehicle, such as sterile, pyrogen-free water, before use. An active compound may also be formulated as long-acting depot preparations, which may be administered by intramuscular injection or by implantation, e.g., subcutaneously or intramuscularly. Depot preparations may include, for example, suitable polymeric or hydrophobic materials, or ion-exchange resins. Such long-acting formulations are particularly convenient for prophylactic use. Formulations suitable for pulmonary administration via the buccal cavity are presented such that particles containing an active compound and desirably having a diameter in the range of 0.5 to 7 microns are delivered in the bronchial tree of the recipient. As one possibility such formulations are in the form of finely comminuted powders which may conveniently be presented either in a pierceable capsule, suitably of, for example, gelatin, for use in an inhalation device, or alternatively as a self-propelling formulation i i ti d it bl li id ll t d ti ll th ingredients such as a surfactant and/or a solid diluent. Suitable liquid propellants include propane and the chlorofluorocarbons, and suitable gaseous propellants include carbon dioxide. Self-propelling formulations may also be employed wherein an active compound is dispensed in the form of droplets of solution or suspension. Such self-propelling formulations are analogous to those known in the art and may be prepared by established procedures. Suitably they are presented in a container provided with either a manually-operable or automatically functioning valve having the desired spray characteristics; advantageously the valve is of a metered type delivering a fixed volume, for example, 25 to 100 microlitres, upon each operation thereof. As a further possibility an active compound may be in the form of a solution or suspension for use in an atomizer or nebuliser whereby an accelerated airstream or ultrasonic agitation is employed to produce a fine droplet mist for inhalation. Formulations suitable for nasal administration include preparations generally similar to those described above for pulmonary administration. When dispensed such formulations should desirably have a particle diameter in the range 10 to 200 microns to enable retention in the nasal cavity; this may be achieved by, as appropriate, use of a powder of a suitable particle size or choice of an appropriate valve. Other suitable formulations include coarse powders having a particle diameter in the range 20 to 500 microns, for administration by rapid inhalation through the nasal passage from a container held close up to the nose, and nasal drops comprising 0.2 to 5% w/v of an active compound in aqueous or oily solution or suspension. Pharmaceutically acceptable carriers are well known to those skilled in the art and include, but are not limited to, 0.1 M and preferably 0.05 M phosphate buffer or 0.8% saline. Additionally, such pharmaceutically acceptable carriers may be aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media. Parenteral vehicles include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's or fixed oils. Preservatives and other additives may also be present, such as, for example, antimicrobials, antioxidants, chelating agents, inert gases and the like. Formulations suitable for topical formulation may be provided for example as gels, creams or ointments. Such preparations may be applied e.g. to a wound or ulcer either directly spread upon the surface of the wound or ulcer or carried on a suitable support such as a bandage, gauze, mesh or the like which may be applied to and over the area to be treated. Liquid or powder formulations may also be provided which can be sprayed or sprinkled directly onto the site to be treated, e.g. a wound or ulcer. Alternatively, a carrier such as a bandage, gauze, mesh or the like can be sprayed or sprinkle with the formulation and then applied to the site to be treated. According to a further aspect of the invention, there is provided a process for the preparation of a pharmaceutical or veterinary composition as described above, the process comprising bringing the active compound(s) into association with the carrier, for example by admixture. In general, the formulations are prepared by uniformly and intimately bringing into association the active agent with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product. The invention extends to methods for preparing a pharmaceutical composition comprising bringing a compound as described herein into conjunction or association with a pharmaceutically or veterinarily acceptable carrier or vehicle. SALTS/ESTERS The compounds of the invention can be present as salts or esters, in particular pharmaceutically and veterinarily acceptable salts or esters. Pharmaceutically acceptable salts of the compounds of the invention include suitable acid addition or base salts thereof. A review of suitable pharmaceutical salts may be found in Berge et al, J Pharm Sci, 66, 1-19 (1977). Salts are formed, for example with strong inorganic acids such as mineral acids, e.g. hydrohalic acids such as hydrochloride, hydrobromide and hydroiodide, sulphuric acid, phosphoric acid sulphate, bisulphate, hemisulphate, thiocyanate, persulphate and sulphonic acids; with strong organic carboxylic acids, such as alkanecarboxylic acids of 1 to 4 carbon atoms which are unsubstituted or substituted (e.g., by halogen), such as acetic acid; with saturated or unsaturated dicarboxylic acids, for example oxalic, malonic, succinic, maleic, fumaric, phthalic or tetraphthalic; with hydroxycarboxylic acids, for example ascorbic, glycolic, lactic, malic, tartaric or citric acid; with aminoacids, for example aspartic or glutamic acid; with benzoic acid; or with organic sulfonic acids, such as (C ₁ -C ₄ )-alkyl- or aryl-sulfonic acids which are unsubstituted or substituted (for example, by a halogen) such as methane- or p-toluene sulfonic acid. Salts which are not pharmaceutically or veterinarily acceptable may still be valuable as intermediates. Preferred salts include, for example, acetate, trifluoroacetate, lactate, gluconate, citrate, tartrate, maleate, malate, pantothenate, adipate, alginate, aspartate, benzoate, butyrate, digluconate, cyclopentanate, glucoheptanate, glycerophosphate, oxalate, heptanoate, hexanoate, fumarate, nicotinate, palmoate, pectinate, 3-phenylpropionate, picrate, pivalate, proprionate, tartrate, lactobionate, pivolate, camphorate, undecanoate and succinate, organic sulphonic acids such as methanesulphonate, ethanesulphonate, 2-hydroxyethane sulphonate, camphorsulphonate, 2-naphthalenesulphonate, benzenesulphonate, p- chlorobenzenesulphonate and p-toluenesulphonate; and inorganic acids such as hydrochloride, hydrobromide, hydroiodide, sulphate, bisulphate, hemisulphate, thiocyanate, persulphate, phosphoric and sulphonic acids. Esters are formed either using organic acids or alcohols/hydroxides, depending on the functional group being esterified. Organic acids include carboxylic acids, such as alkanecarboxylic acids of 1 to 12 carbon atoms which are unsubstituted or substituted (e.g., by halogen), such as acetic acid; with saturated or unsaturated dicarboxylic acid, for example oxalic, malonic, succinic, maleic, fumaric, phthalic or tetraphthalic; with hydroxycarboxylic acids, for example ascorbic, glycolic, lactic, malic, tartaric or citric acid; with aminoacids, for example aspartic or glutamic acid; with benzoic acid; or with organic sulfonic acids, such as (C ₁ -C ₄ )-alkyl- or aryl-sulfonic acids which are unsubstituted or substituted (for example, by a halogen) such as methane or p-toluene sulfonic acid. Suitable hydroxides include inorganic hydroxides, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminium hydroxide. Alcohols include alkanealcohols of 1- 12 carbon atoms which may be unsubstituted or substituted, e.g. by a halogen). ENANTIOMERS/TAUTOMERS In all aspects of the present invention previously discussed, the invention includes, where appropriate all enantiomers, diastereoisomers and tautomers of the compounds of the invention. The person skilled in the art will recognise compounds that possess optical properties (one or more chiral carbon atoms) or tautomeric characteristics. The corresponding enantiomers and/or tautomers may be isolated/prepared by methods known in the art. Enantiomers are characterised by the absolute configuration of their chiral centres and described by the R- and S-sequencing rules of Cahn, Ingold and Prelog. Such conventions are well known in the art (e.g. see ‘Advanced Organic Chemistry’, 3 ^rd edition, ed. March, J., John Wiley and Sons, New York, 1985). Compounds of the invention containing a chiral centre may be used as a racemic mixture, an enantiomerically enriched mixture, or the racemic mixture may be separated using well- known techniques and an individual enantiomer may be used alone. STEREO AND GEOMETRIC ISOMERS Some of the compounds of the invention may exist as stereoisomers and/or geometric isomers – e.g. they may possess one or more asymmetric and/or geometric centres and so may exist in two or more stereoisomeric and/or geometric forms. The present invention contemplates the use of all the individual stereoisomers and geometric isomers of those compounds, and mixtures thereof. The terms used in the claims encompass these forms, provided said forms retain the appropriate functional activity (though not necessarily to the same degree). The present invention also includes all suitable isotopic variations of the compound or a pharmaceutically acceptable salt thereof. An isotopic variation of a compound of the present invention or a pharmaceutically acceptable salt thereof is defined as one in which at least one atom is replaced by an atom having the same atomic number but an atomic mass different from the atomic mass usually found in nature. Examples of isotopes that can be incorporated into the agent and pharmaceutically acceptable salts thereof include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulphur, fluorine and chlorine such as ² H, ³ H, ¹³ C, ¹⁴ C, ¹⁵ N, ¹⁷ O, ¹⁸ O, ³¹ P, ³² P, ³⁵ S, ¹⁸ F and ³⁶ Cl, respectively. Certain isotopic variations of the agent and pharmaceutically acceptable salts thereof, for example, those in which a radioactive isotope such as ³ H or ¹⁴ C is incorporated, are useful in drug and/or substrate tissue distribution studies. Tritiated, i.e., ³ H, and carbon-14, i.e., ¹⁴ C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with isotopes such as deuterium, i.e., ² H, may afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life or reduced dosage requirements and hence may be preferred in some circumstances. For example, the invention includes compounds of general formula (I) where any hydrogen atom has been replaced by a deuterium atom. Isotopic variations of the agent of the present invention and pharmaceutically acceptable salts thereof of this invention can generally be prepared by conventional procedures using appropriate isotopic variations of suitable reagents. ATROPISOMERS Some of the compounds of the invention may exist as atropisomers. Atropisomers are stereoisomers arising because of hindered rotation about a single bond, where energy differences due to steric strain or other contributors create a barrier to rotation that is high enough to allow for isolation of individual conformers. The invention encompasses all such atropisomers. The invention also encompasses rotamers of the compounds. PRODRUGS The invention further includes the compounds of the present invention in prodrug form, i.e. covalently bonded compounds which release the active parent drug in vivo. Such prodrugs are generally compounds of the invention wherein one or more appropriate groups have been modified such that the modification may be reversed upon administration to a human or mammalian subject. Reversion is usually performed by an enzyme naturally present in such subject, though it is possible for a second agent to be administered together with such a prodrug in order to perform the reversion in vivo. Examples of such modifications include ester (for example, any of those described above), wherein the reversion may be carried out be an esterase etc. Other such systems will be well known to those skilled in the art. SOLVATES The present invention also includes solvate forms of the compounds of the present invention. The terms used in the claims encompass these forms. Preferably the solvate is a hydrate. COMBINATIONS A further aspect of the invention relates to a combination comprising a compound as described herein and one or more additional active agents. In a particularly preferred embodiment, the one or more compounds of the invention are administered in combination with one or more additional active agents, for example, existing drugs available on the market. In such cases, the compounds of the invention may be administered consecutively, simultaneously or sequentially with the one or more other active agents. Drugs in general are more effective when used in combination. In particular, combination therapy is desirable in order to avoid an overlap of major toxicities, mechanism of action and resistance mechanism(s). Furthermore, it is also desirable to administer most drugs at their maximum tolerated doses with minimum time intervals between such doses. The major advantages of combining chemotherapeutic drugs are that it may promote additive or possible synergistic effects through biochemical interactions and also may decrease the emergence of resistance. Beneficial combinations may be suggested by studying the activity of the test compounds with agents known or suspected of being valuable in the treatment of a particular disorder. This procedure can also be used to determine the order of administration of the agents, i.e. before, simultaneously, or after delivery. Such scheduling may be a feature of all the active agents identified herein. In the context of cancer, compounds of the invention can be used in combination with immunotherapies such as cancer vaccines and/or with other immune-modulators such as agents that block the PD1/PDL-1 interaction. Other examples of agents for use in combination with the presently claimed compounds include immune modulators that block CTLA-4 or LAG-3. Thus, in one preferred embodiment, the additional active agent is an immunotherapy agent, more preferably a cancer immunotherapy agent. An “immunotherapy agent“ refers to a treatment that uses the subject’s own immune system to fight diseases such as cancer. For other disorders the compounds of the invention can be used in combination agents that block or decrease inflammation such as antibodies that target pro-inflammatory cytokines. The compounds of the invention can also be used in combination with other chemotherapy agents and/or in conjunction with radiotherapy. POLYMORPHS The invention further relates to the compounds of the present invention in their various crystalline forms, polymorphic forms and (an)hydrous forms. It is well established within the pharmaceutical industry that chemical compounds may be isolated in any of such forms by slightly varying the method of purification and or isolation form the solvents used in the synthetic preparation of such compounds. ADMINISTRATION The pharmaceutical compositions of the present invention may be adapted for rectal, nasal, intrabronchial, topical (including buccal and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous, intraarterial and intradermal), intraperitoneal or intrathecal administration. Preferably the formulation is an orally administered formulation. The formulations may conveniently be presented in unit dosage form, i.e., in the form of discrete portions containing a unit dose, or a multiple or sub-unit of a unit dose. By way of example, the formulations may be in the form of tablets and sustained release capsules, and may be prepared by any method well known in the art of pharmacy. Formulations for oral administration in the present invention may be presented as: discrete units such as capsules, gellules, drops, cachets, pills or tablets each containing a predetermined amount of the active agent; as a powder or granules; as a solution, emulsion or a suspension of the active agent in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion; or as a bolus etc. Preferably, these compositions contain from 1 to 250 mg and more preferably from 10-100 mg, of active ingredient per dose. For compositions for oral administration (e.g. tablets and capsules), the term “acceptable carrier” includes vehicles such as common excipients e.g. binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, polyvinylpyrrolidone (Povidone), methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxypropyl-methylcellulose, sucrose and starch; fillers and carriers, for example corn starch, gelatin, lactose, sucrose, microcrystalline cellulose, kaolin, mannitol, dicalcium phosphate, sodium chloride and alginic acid; and lubricants such as magnesium stearate, sodium stearate and other metallic stearates, glycerol stearate stearic acid, silicone fluid, talc waxes, oils and colloidal silica. Flavouring agents such as peppermint, oil of wintergreen, cherry flavouring and the like can also be used. It may be desirable to add a colouring agent to make the dosage form readily identifiable. Tablets may also be coated by methods well known in the art. A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active agent in a free flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, preservative, surface-active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered d i t d ith i t li id dil t Th t bl t b ti ll b t d or scored and may be formulated so as to provide slow or controlled release of the active agent. Other formulations suitable for oral administration include lozenges comprising the active agent in a flavoured base, usually sucrose and acacia or tragacanth; pastilles comprising the active agent in an inert base such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active agent in a suitable liquid carrier. Other forms of administration comprise solutions or emulsions which may be injected intravenously, intraarterially, intrathecally, subcutaneously, intradermally, intraperitoneally or intramuscularly, and which are prepared from sterile or sterilisable solutions. Injectable forms typically contain between 10 - 1000 mg, preferably between 10 - 250 mg, of active ingredient per dose. The pharmaceutical compositions of the present invention may also be in form of suppositories, pessaries, suspensions, emulsions, lotions, ointments, creams, gels, sprays, solutions or dusting powders. An alternative means of transdermal administration is by use of a skin patch. For example, the active ingredient can be incorporated into a cream consisting of an aqueous emulsion of polyethylene glycols or liquid paraffin. The active ingredient can also be incorporated, at a concentration of between 1 and 10% by weight, into an ointment consisting of a white wax or white soft paraffin base together with such stabilisers and preservatives as may be required. DOSAGE A person of ordinary skill in the art can easily determine an appropriate dose of one of the instant compositions to administer to a subject without undue experimentation. Typically, a physician will determine the actual dosage which will be most suitable for an individual patient and it will depend on a variety of factors including the activity of the specific compound employed, the metabolic stability and length of action of that compound, the age, body weight, general health, sex, diet, mode and time of administration, rate of excretion, drug combination, the severity of the particular condition, and the individual undergoing therapy. The dosages disclosed herein are exemplary of the average case. There can of course be individual instances where higher or lower dosage ranges are merited, and such ithi th f thi i ti The dosage amount will further be modified according to the mode of administration of the compound. For example, to achieve an “effective amount” for acute therapy, parenteral administration of a compound is typically preferred. An intravenous infusion of the compound in 5% dextrose in water or normal saline, or a similar formulation with suitable excipients, is most effective, although an intramuscular bolus injection is also useful. Typically, the parenteral dose will be about 0.01 to about 100 mg; preferably between 0.1 and 20 mg, in a manner to maintain the concentration of drug in the plasma at a concentration effective to modulate GPR65. The compounds may be administered one to four times daily at a level to achieve a total daily dose of about 0.4 to about 400 mg. The precise amount of an inventive compound which is therapeutically effective, and the route by which such compound is best administered, is readily determined by one of ordinary skill in the art by comparing the blood level of the agent to the concentration required to have a therapeutic effect. The compounds of this invention may also be administered orally to the patient, in a manner such that the concentration of drug is sufficient to achieve one or more of the therapeutic indications disclosed herein. Typically, a pharmaceutical composition containing the compound is administered at an oral dose of between about 0.1 to about 500 mg or about 0.1 to about 50 mg in a manner consistent with the condition of the patient. Preferably the oral dose would be about 0.5 to about 50 mg or about 0.5 to about 20 mg. No unacceptable toxicological effects are expected when compounds of the present invention are administered in accordance with the present invention. The compounds of this invention, which may have good bioavailability, may be tested in one of several biological assays to determine the concentration of a compound which is required to have a given pharmacological effect. PROCESS A further aspect of the invention relates to a process for preparing compounds of formula (I), as defined herein, said process comprising the steps of: 1) treating a compound of formula (II) where B is as defined above, with triphosgene in the presence of a base, and 2) reacting the mixture so formed with a compound of formula (III), where Z, Y and A are as defined above, in the presence of a base, to form a compound of formula (I): Preferably, the reaction takes place in an organic solvent. Suitable organic solvents include, but are not limited to, dichloromethane, tetrahydrofuran and dimethylformamide, or mixtures of two or more thereof. Preferably, the solvent is dichloromethane. Preferably, the base in step 1) is DMAP. Preferably, the base in step 2) is Et ₃ N. The skilled person would understand that other bases and solvents would also be suitable. The invention is further described by the way of the following non-limiting examples. EXAMPLES Where the preparation of starting materials is not described, these are commercially available, known in the literature, or readily obtainable by those skilled in the art using standard procedures. Where it is indicated that compounds were prepared analogously to earlier examples or intermediates, it will be appreciated by the skilled person that the reaction time, number of equivalents of reagents, solvent, concentration and temperature can be modified for each specific reaction and that it may be necessary or desirable to employ different work-up or purification techniques. General Schemes Abbreviations A list of some common abbreviations is shown below – where other abbreviations are used which are not listed, these will be understood by the person skilled in the art. AIBN: Azobisisobutyronitrile; br.: broad; d: doublet; DCM: dichloromethane; DMSO: dimethylsulfoxide; DPPF: 1,1′-Bis(diphenylphosphino)ferrocene; (ES+): electrospray ionization positive mode; Et ₃ N: triethylamine; EtOAc: ethyl acetate; EtOH: ethanol; h: hours; HPLC: high performance liquid chromatography; Hz: hertz; J: coupling constant; l: litre; M: molar; m: multiplet; [M+H]+: protonated molecular ion; MeCN: acetonitrile; MeOH: methanol; MHz: megahertz; min: minutes; ml: millilitres; MS: mass spectrometry; m/z: mass-to-charge ratio; NBS: N-Bromosuccinimide; NMO: N-Methylmorpholine-N-Oxide; NMR: nuclear magnetic resonance; PDA: photodiode array; RT: room temperature; Rt: retention time; s: singlet; STAB: sodium triacetoxyborohydride; t:triplet; THF: tetrahydrofuran; TLC: thin layer chromatography; UPLC: ultra performance liquid chromatography; UV: ultra-violet. Other abbreviations are intended to convey their generally accepted meaning. General experimental conditions All starting materials and solvents were obtained either from commercial sources or prepared according to literature methods. The appropriate isocyanate and aniline starting materials were obtained from Sigma Aldrich, Fluorochem or Enamine store, or were synthesised as described herein. Reaction mixtures were magnetically stirred and reactions performed at room temperature (approximately 20 °C) unless otherwise indicated. Silica gel chromatography was performed on an automated flash chromatography system, such as CombiFlash Companion, CombiFlash Rf system or Reveleris X2 flash system using RediSep® Rf or Reveleris® or the GraceResolv™ pre-packed silica (230-400 mesh, 40-63 µm) cartridges. Analytical UPLC-MS experiments to determine retention times and associated mass ions were performed using a Waters ACQUITY UPLC ^® H-Class system, equipped with ACQUITY PDA Detector and ACQUITY QDa mass spectrometer or Waters SQD mass spectrometer, running the analytical method described below. Preparative HPLC purifications were performed either using a Waters Xbridge Prep OBD C18, 10 µm, 40 x 150 mm column using a gradient of MeCN and 0.1% ammonia in water or a gradient of MeCN and 0.1% formic acid in water. Fractions were collected following UV detection across all wavelengths with PDA and in some cases an SQD2 or ACQUITY QDa mass spectrometer. Analytical SFC experiments to determine retention times were performed using a Waters SFC system UPC2 system with a column temperature of 40 °C and a back pressure (ABPR) of 1750 psi using one of the analytical methods described. Preparative HPLC purifications were performed either using a Waters Xbridge Prep OBD C18, 10 µm, 40 x 150 mm column using a gradient of MeCN and 0.1% ammonia in water or a gradient of MeCN and 0.1% formic acid in water. Fractions were collected following UV detection across all wavelengths with PDA and in some cases an SQD2 or ACQUITY QDa mass spectrometer. Preparative SFC purifications were performed using either a Waters SFC prep 15 system, a Waters SFC prep 100 system or a Sepiatec Prep SFC 50 with either a: Phenomenex Lux® Cellulose-4, Column 1 x 25 cm, 5 µm particle size column or a Chiralpak® IG (Daicel Ltd.) column (1 x 25 cm, 5 µm particle size) or a Chiralpak IC 10 x 250 mm 5 µm particle size column or a Chiralpak IA 10 x 250 mm 5 µm particle size column or a Phenomenex Lux® 5 µm i-Cellulose-5, LC Column 250 x 21 mm or a a Phenomenex Lux® A15 µm, LC Column 250 x 10 mm or a Chiralpak IH 10 x 250 mm, 5 ^m particle size column or a Chiralpak AY-H 10 x 250 mm, 5 ^m particle size column, flow rate 15 – 65 ml/min eluting with a mixture of CO ₂ and co-solvent (MeOH, EtOH or IPA). Fractions were collected following UV detection at 210 – 400 nm using a PDA. NMR spectra were recorded using either a Bruker Avance III HD 500 MHz instrument, a Bruker Avance Neo 400 MHz, Bruker Avance III 400 MHz instrument or a QOne AS400400 MHz spectrometer using either residual non-deuterated solvent, or tetra-methylsilane as a reference Analytical methods Method 1 – Basic 3 min method Column: Waters ACQUITY UPLC® BEH C18, 1.7 µm, 2.1 x 30 mm at 40 °C Detection: UV at 210-400 nm unless otherwise indicated, MS by electrospray ionisation Solvents: A: 0.1% Ammonia in water, B: MeCN Gradient: Method 2 – Acidic 3 min method 1 Column: Waters CSH C18, 1.7 µm, 2.1 x 30 mm at 40 °C Detection: UV at 210-400 nm unless otherwise indicated, MS by electrospray ionisation Solvents: A: 0.1% formic acid in water, B: MeCN Gradient: Method 3 – Acidic 5 min method 1 Column: Agilent EclipsePlus RRHD C18, 1.8 μm, 3.0 x 50 mm at 25 °C Detection: UV at 214 and 254 nm unless otherwise indicated, MS by electrospray ionisation Solvents: A: 0.05% formic acid in water, B: 0.05% formic acid in MeCN Gradient: Method 4 – Acidic 5 min method 2 Column: Waters Sunfire, 3.5 μm, 4.6 x 50 mm column at 25 °C Detection: UV at 214 and 254 nm unless otherwise indicated, MS by electrospray ionisation Solvents: A: 0.05% formic acid in water, B: 0.05% formic acid in MeCN Gradient: Method 5 – Acidic 3 min method 2 Column: Waters CORTECS UPLC,C18, 1.6 μm, 2.1 x 50 mm column at 25 °C Detection: UV at 210-400 nm unless otherwise indicated, MS by electrospray ionisation Solvents: A: 0.1% formic acid in water, B: MeCN Gradient: Experimental scheme 1 Compound 1: N-(5-Bromo-2-fluoro-4-(trifluoromethyl)phenyl)-6-oxo-3,4,6,7 -tetrahydro-2,7- naphthyridine-2(1H)-carboxamide To a solution of triphosgene (14.5 mg, 48.8 µmol) in DCM (1.5 ml) was added a solution of 5-bromo-2-fluoro-4-(trifluoromethyl)aniline (31.5 mg, 122 µmol) and DMAP (47.7 mg, 3.2 Eq, 390 µmol) in DCM (1.5 ml) and the resulting mixture was stirred at RT for 30 min. This solution was added to a solution of 5,6,7,8-tetrahydro-2,7-naphthyridin-3(2H)-one, HBr (28.2 mg, 122 µmol) and Et ₃ N (51.0 µl, 366 µmol) in DCM (1.5 ml) and the reaction was stirred at RT for 1.5 h. The resulting mixture was directly loaded onto silica and the product was purified by chromatography on silica gel (0-6% MeOH/DCM) to afford N-(5-bromo-2-fluoro- 4-(trifluoromethyl)phenyl)-6-oxo-3,4,6,7-tetrahydro-2,7-naph thyridine-2(1H)-carboxamide 1 as a light white solid. LCMS (Method 1) m/z 434.1, 436.2 (M+H) ⁺ (ES ⁺ ), at 1.21 min. ¹ H NMR (400 MHz, DMSO-d6) δ 11.41 (s, 1H), 8.70 (s, 1H), 8.15 (d, J = 7.2 Hz, 1H), 7.78 (d, J = 11.2 Hz, 1H), 7.33 (s, 1H), 6.20 (s, 1H), 4.40 (s, 2H), 3.61 (t, J = 6.1 Hz, 2H), 2.77 (t, J = 6.1 Hz, 2H) The following compounds were prepared using appropriate starting materials in an analogous procedure to that described in Experimental Scheme 1. Where the starting materials are not described in the literature, their synthesis is described below.

Key (a) Reaction run with Et ₃ N and no DMAP; (b) Product purified by chromatography on silica (EtOH/EtOAc); (c) Product purified by reverse phase HPLC; (d) Mass (M-H) observed in (ES-) (e) Product purified by trituration from DCM/ isohexane; (f) Product purified by reverse phase flash chromatography; (g) Product purified by chromatography on silica (EtOAc/isohexane); (h) Product purified by Prep TLC; (i) product isolated by filtration of reaction mixture; (j) Product purified by chromatography on silica (0-15% MeOH/DCM); (k) Product purified by chromatography on silica (0-10 % (0.7 M ammonia in MeOH/DCM); (l) 2% NH ₄ OH in 3:1 EtOH/EtOAc) in isohexane; (m) synthesised using I-6 and oxidation occurred during urea formation Intermediate 1 (I-1)

Step 1: To a solution of 4-bromo-6-fluoronicotinaldehyde I-1a (1 g, 4.90 mmol) in DCE (10 ml) was added prop-2-en-1-amine (280 mg, 4.90 mmol) and STAB (2.08 g, 9.8 mmol). The mixture was stirred at RT for 16 h before being diluted with a saturated aqueous NaHCO ₃ solution (15 ml) and the product was extracted with DCM (3 x 5 ml). The combined organics were dried over Na ₂ SO ₄ , filtered and concentrated in vacuo to give N-((4-bromo-6- fluoropyridin-3-yl)methyl)prop-2-en-1-amine I-1b as a colourless oil, which was used in the next step without any further purification. LCMS (Method 3) m/z 245.0, 247.0 (M+H) ⁺ (ES ⁺ ), at 0.30 min. Step 2: To a solution of N-((4-bromo-6-fluoropyridin-3-yl)methyl)prop-2-en-1-amine I-1b (1.65 g, 6.73 mmol) and Et ₃ N (1.87 ml, 13.46 mmol) in DCM (15 ml) was added di-tert-butyl dicarbonate (2.2 g, 10.10 mmol). The resultant mixture was stirred at RT for 16 h and then diluted with water (15 ml) and the product was extracted with DCM (3 x 5 ml). The combined organics were dried over Na ₂ SO ₄ , filtered and concentrated in vacuo. The product was purified by chromatography on silica gel (3% EtOAc/petroleum ether) to give tert-butyl allyl((4-bromo-6-fluoropyridin-3-yl)methyl)carbamate I-1c as a colourless oil. ¹ H NMR (400 MHz, DMSO-d6) δ 8.03 (s, 1H), 7.67 (d, J = 2.8 Hz, 1H), 5.83 – 5.73 (m, 1H), 5.15 – 5.07 (m, 2H), 4.42 (s, 2H), 3.85 (s, 2H), 1.43 – 1.35 (m, 9H). Step 3: To a solution of tert-butyl allyl((4-bromo-6-fluoropyridin-3-yl)methyl)carbamate I-1c (490 mg, 1.42 mmol) in DMF (5 ml) were added Pd(OAc) ₂ (32 mg, 0.14 mmol), K ₂ CO ₃ (294 mg, 2.13 mmol) and PPh ₃ (75 mg, 0.28 mmol). The reaction mixture was stirred at 80 °C under N ₂ for 16 h before being diluted with water (50 ml) and the product was extracted with concentrated in vacuo. The product was purified by chromatography on silica gel (5-10% etOAc/ petroleum ether) to give tert-butyl 6-fluoro-4-methyl-2,7-naphthyridine-2(1H)- carboxylate I-1d as a colourless oil. ¹ H NMR (400 MHz, DMSO-d6) δ 8.02 (s, 1H), 7.02 (s, 1H), 6.84 (d, J = 1.2 Hz, 1H), 4.73 (s, 2H), 1.97 – 1.96 (m, 3H), 1.48 (s, 9H). tert-butyl 6-fluoro-4-methylene-3,4-dihydro-2,7-naphthyridine-2(1H)-car boxylate I-1e was also obtained from the purification Step 4: To a mixture of tert-butyl 6-fluoro-4-methyl-2,7-naphthyridine-2(1H)-carboxylate I-1d (50 mg, 0.19 mmol) in MeOH (3 ml) was added Pd/C (5 mg, 10% w/w). The mixture was stirred at RT under a H ₂ atmosphere for 16 h before being filtered through Celite and the filtrate was concentrated in vacuo to give tert-butyl 6-fluoro-4-methyl-3,4-dihydro-2,7- naphthyridine-2(1H)-carboxylate) I-1f as a colourless oil, which was used in the next step without further purification. ¹ H NMR (400 MHz, DMSO-d6) δ 8.09 (s, 1H), 7.10 (s, 1H), 4.69 – 4.64 (m, 1H), 4.43 (s, 1H), 3.55 – 3.50 (m, 1H), 3.40 (s, 1H), 3.04 – 2.96 (m, 1H), 1.43 (s, 9H), 1.21 (d, J = 6.8 Hz, 3H). Step 5: A solution of tert-butyl 6-fluoro-4-methyl-3,4-dihydro-2,7-naphthyridine-2(1H)- carboxylate I-1f (30 mg, 0.11 mmol) in a solution of HCl in 1,4-dioxane (2 ml, 4 M, 8 mmol) was stirred at RT for 2 h. The reaction mixture was concentrated in vacuo to give 6-fluoro-4- methyl-1,2,3,4-tetrahydro-2,7-naphthyridine hydrochloride I-1 as a yellow solid. LCMS (Method 3) m/z 167.1 (M+H) ⁺ (ES ⁺ ), at 0.34 min. Intermediate 2 (I-2) Step 1: To a solution of tert-butyl 6-fluoro-4-methyl-3,4-dihydro-2,7-naphthyridine-2(1H)- carboxylate I-1e (150 mg, 0.56 mmol) in MeOH (5 ml) was added NaOMe (304 mg, 5.63 mmol). The resultant mixture was stirred at 70 °C for 16 h. The reaction mixture was diluted with water (10 ml) and the product was extracted with DCM (3 x 5 ml). The combined organics were dried over Na ₂ SO ₄ , filtered and concentrated in vacuo to give tert-butyl 6- methoxy-4-methyl-3,4-dihydro-2,7-naphthyridine-2(1H)-carboxy late I-2a as a colourless oil, which was used in the next step without any further purification. ¹ H NMR (400 MHz, DMSO- d6) δ 7.99 (s, 1H), 6.68 (s, 1H), 4.60 – 4.56 (m, 1H), 4.35 (s, 1H), 3.81 (s, 3H), 3.52 – 3.48 (m 1H) 340 (s 1H) 295 – 287 (m 1H) 142 (s 9H) 118 (d J = 68 Hz 3H) Step 2: A mixture of tert-butyl 6-methoxy-4-methyl-3,4-dihydro-2,7-naphthyridine-2(1H)- carboxylate I-2a (130 mg, 0.47 mmol) in HBr (2 ml, 48% w/w in water) was stirred at 95 °C for 16 h. The reaction mixture was concentrated in vacuo to give 5-methyl-5,6,7,8- tetrahydro-2,7-naphthyridin-3(2H)-one hydrobromide I-2 as an orange solid, which was used in the next step without any further purification. LCMS (Method 3) m/z 165.1 (M+H) ⁺ (ES ⁺ ), at 0.27 min. Intermediate 3 (I-3) A mixture of tert-butyl 6-fluoro-4-methylene-3,4-dihydro-2,7-naphthyridine-2(1H)-car boxylate I-1e (90 mg, 0.34 mmol) in a solution of HCl in 1,4-dioxane (2 ml, 4 M, 8 mmol) was stirred at RT for 2 h. The reaction mixture was concentrated in vacuo to give 6-fluoro-4-methylene- 1,2,3,4-tetrahydro-2,7-naphthyridine hydrochloride I-3 as a light yellow solid. LCMS (Method 3) m/z 165.1 (M+H) ⁺ (ES ⁺ ), at 0.46 min. Intermediate 4 (I-4) Step 1: N-((3-Bromo-2-fluoropyridin-4-yl)methyl)prop-2-en-1-amine I-4b was synthesised from 3-bromo-2-fluoroisonicotinaldehyde I-4a using a procedure essentially the same as for I-1b. LCMS (Method 5) m/z 245.0, 247.0 (M+H) ⁺ (ES ⁺ ), at 0.31 min. Step 2: tert-Butyl allyl((3-bromo-2-fluoropyridin-4-yl)methyl)carbamate I-4c was synthesised from N-((3-bromo-2-fluoropyridin-4-yl)methyl)prop-2-en-1-amine I-4b using a procedure essentially the same as for I-1c. ¹ H NMR (400 MHz, DMSO-d6) δ 8.20 (d, J = 4.8 Hz, 1H), 7.13 (s, 1H), 5.87 – 5.75 (m, 1H), 5.18 – 5.10 (m, 2H), 4.43 (s, 2H), 3.93 – 3.87 (m, 2H), 1.42 – 1.26 (m, 9H). Step 3: To a solution of tert-butyl allyl((3-bromo-2-fluoropyridin-4-yl)methyl)carbamate I-4c (230 mg, 0.67 mmol) in ethylene glycol (2 ml) and DMSO (2 ml) were added Pd(OAc) ₂ (7.5 mg, 0.03 mmol), KOAc (98 mg, 0.99 mmol) and dppf (28 mg, 0.05 mmol). The reaction mixture was stirred at 120 °C under N ₂ atmosphere in a sealed tube for 16 h before being diluted with water (15 ml) and the product was extracted with EtOAc (3 x 5 ml). The combined organics were dried over Na ₂ SO ₄ , filtered and concentrated in vacuo. The product was purified by prep-TLC (20% EtOAc/petroleum ether) to give tert-butyl 5-fluoro-4- methylene-3,4-dihydro-2,6-naphthyridine-2(1H)-carboxylate I-4d as a colourless oil. ¹ H NMR (400 MHz, DMSO-d6) δ 8.06 (d, J = 5.2 Hz, 1H), 7.31 (d, J = 4.8 Hz, 1H), 5.80 (s, 1H), 5.49 (d, J = 3.2 Hz, 1H), 4.67 (s, 2H), 4.17 (s, 2H), 1.41 (s, 9H). Step 4: tert-Butyl 5-fluoro-4-methyl-3,4-dihydro-2,6-naphthyridine-2(1H)-carbox ylate I-4e was synthesised from tert-butyl 5-fluoro-4-methylene-3,4-dihydro-2,6-naphthyridine-2(1H)- carboxylate I-4d using a procedure essentially the same as for I-1f. ¹ H NMR (400 MHz, DMSO-d6) δ 8.00 (d, J = 5.2 Hz, 1H), 7.19 (d, J = 4.8 Hz, 1H), 4.96 – 4.86 (m, 1H), 4.36 – 4.20 (m, 1H), 4.01 – 3.90 (m, 1H), 3.25 – 3.06 (m, 2H), 1.43 (s, 9H), 1.14 (d, J = 6.4 Hz, 3H). Step 5: 5-Fluoro-4-methyl-1,2,3,4-tetrahydro-2,6-naphthyridine hydrochloride I-4 was synthesised from tert-butyl 5-fluoro-4-methyl-3,4-dihydro-2,6-naphthyridine-2(1H)- carboxylate I-4e using a procedure essentially the same as for I-1 ¹ H NMR (400 MHz, DMSO-d6) δ 10.04 – 9.47 (m, 2H), 8.09 (d, J = 5.2 Hz, 1H), 7.27 (d, J = 5.2 Hz, 1H), 4.32 (q, J = 16.8 Hz, 2H), 3.45 – 3.40 (m, 1H), 3.31 – 3.27 (m, 2H), 1.36 (d, J = 6.8 Hz, 3H). Intermediate 5 (I-5) 5-Fluoro-4-methylene-1,2,3,4-tetrahydro-2,6-naphthyridine I-5 was synthesised from tert- butyl 5-fluoro-4-methylene-3,4-dihydro-2,6-naphthyridine-2(1H)-car boxylate I-4d using a procedure essentially the same as for I-1 Intermediate 6 (I-6) Step 1: To a solution of ethyl 3-oxopiperidine-4-carboxylate I-6a (2.0 g, 9.66 mmol) and Et ₃ N (2.62 ml, 19.3 mmol) in DCM (20 ml) was added di-tert-butyl dicarbonate (5.2 g, 24.15 mmol). The reaction mixture was stirred at RT for 16 h and then diluted with water (20 ml) and the product was extracted with EtOAc (2 x 10 ml). The combined organics were dried over Na ₂ SO ₄ and concentrated in vacuo. The product was purified by chromatography on silica gel (20% EtOAc/petroleum ether) to give 1-(tert-butyl) 4-ethyl 3-oxopiperidine-1,4- dicarboxylate I-6b as a yellow oil. ¹ H NMR (400 MHz, DMSO-d6) δ 11.92 (s, 1H), 4.22 – 4.17 (m, 2H), 3.96 (s, 2H), 3.42 – 3.40 (m, 2H), 2.23 – 2.20 (m, 2H), 1.40 (s, 9H), 1.25 – 1.21 (m, 3H). Step 2: To a solution of 1-(tert-butyl) 4-ethyl 3-oxopiperidine-1,4-dicarboxylate I-6b (2.3 g, 8.47 mmol) in toluene (40 ml) and BnOH (4.6 ml) was added DMAP (0.1 g, 0.84 mmol) . The reaction mixture was stirred at RT for 16 h before being diluted with water (30 ml) and the product was extracted with DCM (2 x 30 ml). The combined organics were dried over Na ₂ SO ₄ and concentrated in vacuo. The product was purified by chromatography on silica gel (20% EtOAc/petroleum ether) to give 4-benzyl 1-(tert-butyl) 3-oxopiperidine-1,4- 7.32 (m, 5H), 5.23 (s, 2H), 3.97 (s, 2H), 3.43 – 3.40 (m, 2H), 2.27 – 2.25 (m, 2H), 1.40 (s, 9H). Step 3: To a solution of 4-benzyl 1-(tert-butyl) 3-oxopiperidine-1,4-dicarboxylate I-6c (1 g, 3.00 mmol) in THF (10 ml) was slowly added NaH (240 mg, 6.00 mmol) at 0 °C under N ₂ . The reaction mixture was stirred at RT for 1 h before ethyl 2-bromoacetate (0.66 ml, 6.00 mmol) was added. The reaction mixture was stirred at RT for another 16 h before being quenched with saturated aqueous NH ₄ Cl solution (10 ml) and the product was extracted with EtOAc (2 x 10 ml). The combined organics were washed with brine (10 ml), dried over Na ₂ SO ₄ and concentrated. The product was purified by chromatography on silica gel (205 EtOAc/ petroleum ether) to give 4-benzyl 1-(tert-butyl)4-(2-ethoxy-2-oxoethyl)-3- oxopiperidine-1,4- dicarboxylate I-6d as a yellow oil. ¹ H NMR (400 MHz, DMSO-d6) δ 7.42 – 7.33 (m, 5H), 5.19 – 5.11 (m, 2H), 4.16 – 3.99 (m, 4H), 3.64 – 3.58 (m, 1H), 3.46 – 3.38 (m, 1H), 2.87 – 2.71 (m, 2H), 2.38 – 2.32 (m, 1H), 2.20 – 2.13 (m, 1H), 1.39 (s, 9H), 1.15 (t, J = 7.2 Hz, 3H). Step 4: To a solution of 4-benzyl 1-(tert-butyl) 4-(2-ethoxy-2-oxoethyl)-3-oxopiperidine -1,4- dicarboxylate I-6d (200 mg, 0.48 mmol) in MeOH (5 ml) was added Pd/C (20 mg, 10% w/w). The reaction was stirred at RT for 16 h under an atmosphere of H ₂ and then filtered and the filtrate was concentrated in vacuo. The product was purified by prep-TLC (33% EtOAc/petroleum ether) to give tert-butyl 4-(2-ethoxy-2-oxoethyl)-3-oxopiperidine-1- carboxylate I-6e as a yellow oil. ¹ H NMR (400 MHz, DMSO-d6) δ 4.08 – 3.99 (m, 3H), 3.89 – 3.77 (m, 2H), 3.37 – 3.28 (m, 1H), 2.90 – 2.82 (m, 1H), 2.62 – 2.56 (m, 1H), 2.41 – 2.35 (m, 1H), 2.08 – 2.02 (m, 1H), 1.74 – 1.63 (m, 1H), 1.41 (s, 9H), 1.18 (t, J = 7.2 Hz, 3H). Step 5: To a solution of tert-butyl 4-(2-ethoxy-2-oxoethyl)-3-oxopiperidine-1-carboxylate I- 6e (70 mg, 0.24 mmol) in EtOH (2 ml) was added hydrazine hydrate (0.01 ml, 0.24 mmol 80% w/w). The reaction mixture was stirred at 80 °C for 1 h before being diluted with DCM (5 ml) and H ₂ O (5 ml) and the two layers were separated. The organic layer was dried over Na ₂ SO ₄ and concentrated in vacuo to afford tert-butyl 3-oxo-2,4,4a,5,6,8- hexahydropyrido[3,4-c]pyridazine-7(3H)-carboxylate I-6f as a yellow oil. ¹ H NMR (400 MHz, DMSO-d6) δ 10.60 (s, 1H), 4.31 (d, J = 16.0 Hz, 1H), 4.18 – 3.98 (m, 1H), 3.83 – 3.71 (m, 2H), 3.06 – 2.90 (m, 1H), 2.77 – 2.67 (m, 1H), 2.43 – 2.37 (m, 1H), 2.23 – 2.15 (m, 1H), 1.99 – 1.93 (m, 1H), 1.40 (s, 9H). Step 6: To a solution of tert-butyl 3-oxo-2,4,4a,5,6,8-hexahydropyrido[3,4-c]pyridazine- 7(3H)-carboxylate I-6f (70 mg, 0.24 mmol) in AcOH (1 ml) was added Br ₂ (0.01 ml, 0.24 mmol) The reaction mixture was stirred at 85 °C for 30 min before being concentrated in vacuo to give 4,4a,5,6,7,8-hexahydropyrido[3,4-c]pyridazin-3(2H)-one I-6 as a yellow oil, which was used without any further purification. LCMS (Method 5) m/z 153.9 (M+H) ⁺ (ES ⁺ ), at 0.29 min Intermediate 7 (I-7) Step 1: To a mixture of 3-bromo-2-fluoro-4-methylpyridine I-7a (900 mg, 4.74 mmol) in CCl ₄ (10 ml) were added NBS (1.01 g, 5.68 mmol) and AIBN (78 mg, 0.47 mmol). The mixture was stirred at 80 °C overnight before being concentrated in vacuo and the product was purified by chromatography on silica gel (2%EtOAc/petroleum ether) to give 3-bromo-4- (bromomethyl)-2-fluoropyridine I-7b as a colourless oil. ¹ H NMR (400 MHz, DMSO-d6) δ 8.23 (d, J = 5.2 Hz, 1H), 7.60 (d, J = 4.8 Hz, 1H), 4.75 (s, 2H). Step 2: To a solution of 3-bromo-4-(bromomethyl)-2-fluoropyridine I-7b (540 mg, 2.01 mmol) in MeCN (10 ml) was added NMO (470 mg, 4.02 mmol). The resultant mixture was stirred at RT for 16 h before being concentrated in vacuo and the product was purified by prep-TLC (20% EtOAc/petroleum ether) to give 3-bromo-2-fluoroisonicotinaldehyde I-7c as a white solid. ¹ H NMR (400 MHz, DMSO-d6) δ 10.19 (s, 1H), 8.40 (d, J = 4.8 Hz, 1H), 7.68 (dd, J = 0.4 Hz, 4.8 Hz, 1H) Step 3: To a solution of 3-bromo-2-fluoroisonicotinaldehyde I-7c (220 mg, 1.08 mmol) in toluene (6 ml) and H ₂ O (2 ml) were added potassium tert-butyl N-[2- (trifluoroboranuidyl)ethyl]carbamate (298 mg, 1.19 mmol), Cs ₂ CO ₃ (1.05 g, 3.24 mmol) and PdCl ₂ (dppf) (39 mg, 52.92 μmol). The reaction mixture was stirred at 80 °C for 16 h before being diluted with water (10 ml) and the product was extracted with EtOAc (3 x 5 ml). The combined organics were dried over Na ₂ SO ₄ , filtered and concentrated in vacuo. The product was purified by chromatography on silica gel (33% EtOAc/petroleum ether) to give tert-butyl 5-fluoro-1-hydroxy-3,4-dihydro-2,6-naphthyridine-2(1H)-carbo xylate I-7d as a light yellow oil. ¹ H NMR (400 MHz, DMSO-d6) δ 8.07 (d, J = 4.8 Hz, 1H), 7.32 (d, J = 5.2 Hz, 1H), 6.68 (s, 1H), 6.19 (s, 1H), 4.09 (s, 1H), 3.17 (s, 1H), 2.75 – 2.57 (m, 2H), 1.44 (s, 9H). Step 4: To a mixture of tert-butyl 5-fluoro-1-hydroxy-3,4-dihydro-2,6-naphthyridine-2(1H)- carboxylate I-7d (40 mg, 0.15 mmol) in DCM (10 ml) were added triethylsilane (52 mg, 0.45 mmol) and boron trifluoride diethyl etherate (132 mg, 0.45 mmol, 48% w/w) dropwise at -70 °C. The resultant mixture was stirred at -70 °C for 2 h and then quenchened with a saturated aqueous NaHCO ₃ solution (10 ml) and the product was extracted with DCM (3 x 5 ml). The combined organics were dried over Na ₂ SO ₄ , filtered and concentrated in vacuo to give 5-fluoro-1,2,3,4-tetrahydro-2,6-naphthyridine hydrochloride I-7 as a brown oil, which was used directly without any further purification. LCMS (Method 3) m/z 153.0 (M+H) ⁺ (ES ⁺ ), at 0.39 min Experimental scheme 2 Compound 18: N-(5-Chloro-2-fluoro-4-(trifluoromethyl)phenyl)-3-(methylsul fonyl)-5,8- dihydropyrido[4,3-e][1,2,4]triazine-7(6H)-carboxamide Step 1: To a solution of KOH (12.38 g, 221.07 mmol) in MeOH (60 ml) at 0 °C was added tert-butyl 4-oxopiperidine-1-carboxylate (10 g, 50.25 mmol) in MeOH (60 ml) dropwise. The i t ti d t RT f 30 i b f PhI(OA ) (2427 7537 l) dd d before being stirred at RT for 16 h. The reaction was quenched by the addition of aqueous NH ₄ Cl (100 ml) and the product was extracted with EtOAc (2 x 100 ml). The combined organics were dried over Na ₂ SO ₄ and concentrated in vacuo. The product was purified by chromatography on silica gel (20% EtOAc/ petroleum ether) to give tert-butyl 3-hydroxy-4,4- dimethoxypiperidine-1-carboxylate 18b as a yellow oil. ¹ H NMR (400 MHz, DMSO-d6) δ 4.77 (d, J = 4.4 Hz, 1H), 3.77 (s, 2H), 3.56 (s, 1H), 3.11 (s, 6H), 3.02 – 2.88 (m, 1H), 2.81 – 2.57 (m, 1H), 1.70 – 1.58 (m, 2H), 1.38 (s, 9H). Step 2: To a solution of oxalyl chloride (3.8 ml, 45.98 mmol) in DCM (20 ml) was added dropwise DMSO (6.52 ml, 91.95 mmol) at -70 °C. After 5 min, a solution of tert-butyl 3- hydroxy-4,4-dimethoxypiperidine-1-carboxylate 18b (10 g, 38.31 mmol) in DCM (50 ml) was added dropwise. The reaction was stirred at -70 °C for 20 min, then Et ₃ N (25.5 ml, 183.90 mmol) was added. Water was added and the product was extracted with DCM (100 mL). The organic portion was washed with brine (50 ml), dried over Na ₂ SO ₄ and concentrated in vacuo to give tert-butyl 4,4-dimethoxy-3-oxopiperidine-1-carboxylate 18c as a yellow oil. ¹ H NMR (400 MHz, DMSO-d6) δ 3.98(s, 2H), 3.54 (t, J = 6.0 Hz, 2H), 3.14 (s, 6H), 2.02 (t, J = 6.0Hz, 2H), 1.39 (s, 9H). Step 3: To a solution of tert-butyl 4,4-dimethoxy-3-oxopiperidine-1-carboxylate 18c (9.5 g, 36.68 mmol) in EtOH (100 ml) was added NaOMe (2.18 g, 40.35 mmol) and methyl hydrazinecarbimidothioate hydroiodide (8.55 g, 36.68 mmol). The reaction mixture was stirred at RT for 16 h and then quenched with aqueous NH ₄ Cl (50 ml) and the product was extracted with DCM (2 x 100 ml). The combined organics were washed with brine (500 ml), dried over Na ₂ SO ₄ and concentrated in vacuo. The residue was purified by chromatography on silica gel (1% MeOH/DCM) to give tert-butyl-3-(2-(imino(methylthio)methyl)hydrazono)- 4,4-dimethoxypiperidine-1-carboxylate 18d as a yellow solid. LCMS (Method 5) m/z 346.8 (M+H) ⁺ (ES ⁺ ), at 0.90 min. Step 4: A mixture of tert-butyl-3-(2-(imino(methylthio)methyl)hydrazono)-4,4- dimethoxypiperidine-1-carboxylate 18d (5.7 g, 16.46 mmol) and TsOH (2.83 g, 16.46 mmol) in toluene (100 ml) was stirred at 100 °C for 16 h. The mixture was concentrated in vacuo and the product was purified by chromatography on silica gel (10% EtOAc/petroleum ether) to afford 3-(methylthio)-5,8-dihydropyrido[4,3-e][1,2,4]triazine-7(6H) -carboxylate 18e as a yellow oil. HNMR (400 MHz, DMSO-d6) δ 4.73 (s, 2H), 3.70 (t, J = 6.0 Hz, 2H), 2.91 (t, J = 6.0 Hz, 2H), 2.89 (s, 3H), 1.44 (s, 9H). Step 5: To a solution of tert-butyl 3-(methylthio)-5,8-dihydropyrido[4,3-e][1,2,4]triazine- 7(6H) carboxylate 18e (400 mg 142 mmol) in 14 dioxane (1 ml) was added a solution of HCl in 1,4-dioxane (4 M, 1 ml). The reaction was stirred at RT for 1 h before being concentrated in vacuo to give 3-(methylthio)-5,6,7,8-tetrahydropyrido[4,3-e][1,2,4]triazin e hydrochloride 18f as a yellow solid. LCMS (Method 5) m/z 182.5 (M+H) ⁺ (ES ⁺ ), at 0.30 min. Step 6: To a solution of 5-chloro-2-fluoro-4-(trifluoromethyl)aniline (300 mg, 1.42 mmol) and triphosgene (211 mg, 0.71 mmol) in DCM (5 ml) was added a solution of DMAP (554 mg, 4.54 mmol) in DCM (5 ml) at 0 °C. The resulting mixture was stirred at 0 °C for 30 min and then added dropwise to a solution of 3-(methylthio)-5,6,7,8-tetrahydropyrido[4,3- e][1,2,4]triazine hydrochloride (400 mg, 1.42 mmol) and Et ₃ N (0.4 ml, 2.84 mmol) in DCM (5 ml). The reaction was stirred at RT for 16 h before being diluted with H ₂ O (10 ml) and the product was extracted with DCM (2 x 10 ml). The combined organics were dried over Na ₂ SO ₄ and concentrated in vacuo. The product was purified by chromatography on silica gel (25% EtOAc/ petroleum ether) to give N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-3- (methylthio)-5,8-dihydropyrido[4,3-e][1,2,4]triazine-7(6H)-c arboxamide 18g as a yellow solid. ¹ H NMR (400 MHz, DMSO-d6) δ 9.16 (s, 1H), 7.97 (d, J = 6.8 Hz, 1H), 7.80 (d, J = 10.8 Hz 1H), 4.91 (s, 2H), 3.86 (t, J = 6.0 Hz, 2H), 3.00 (t, J = 6.0 Hz, 2H), 2.61 (s, 3H). Step 7: To a solution of N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-3-(methylthi o)-5,8- dihydropyrido[4,3-e][1,2,4]triazine-7(6H)-carboxamide 18g (370 mg, 0.88 mmol) in DCM (5 ml) was added mCPBA (533 mg, 3.08 mmol) at 0 °C. The reaction was stirred at RT for 16 h. and then quenched by addition of aqueous sodium bisulfite (10 ml). The pH was adjusted to ~7-8 by addition of saturated NaHCO ₃ . The product was extracted with DCM (10 ml). The organics were dried over Na ₂ SO ₄ and concentrated in vacuo before the product was purified by chromatography on silica gel (2% MeOH/ DCM) to give N-(5-chloro-2-fluoro-4- (trifluoromethyl)phenyl)-3-(methylsulfonyl)-5,8-dihydropyrid o[4,3-e][1,2,4]triazine-7(6H)- carboxamide 18 as a yellow solid. LCMS (Method 4) m/z 454 (M+H) ⁺ (ES ⁺ ), at 3.89 min. ¹ H NMR (400 MHz, DMSO-d6) δ 9.24 (s, 1H), 7.98 (d, J = 6.8 Hz, 1H), 7.81 (d, J = 10.8 Hz, 1H), 5.08 (s, 2H), 3.94 (t, J = 6.0 Hz, 2H), 3.52 (s, 3H), 3.20 (t, J = 5.6 Hz, 2H). Experimental scheme 3 Compound 27: N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-4,5-difluoro -3,4-dihydro-2,6- naphthyridine-2(1H)-carboxamide

Step 1: Into a solution of N-(5-chloro-2-fluoro-4- (trifluoromethyl)phenyl)-5-fluoro-4- methylene-3,4-dihydro-2,6-naphthyridine-2(1H)-carboxamide 24 (106 mg, 0.26 mmol) in DCM (5 ml) was bubbled O ₃ at -78 °C for 10 min. The reaction mixture was concentrated in vacuo to give N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-5-fluoro-4-o xo-3,4- dihydro-2,6- naphthyridine-2(1H)-carboxamide 27a which was used in the next step without any further purification. Step 2: To a solution of N-(5-chloro-2-fluoro-4-(trifluoromethyl) phenyl)-5-fluoro-4-oxo-3,4- dihydro-2,6-naphthyridine-2(1H)-carboxamide 27a (106 mg, 0.26 mmol) in MeOH (5 ml) was added NaBH ₄ (20 mg, 0.52 mol) at RT. The reaction mixture was stirred at RT for 1 h before being concentrated in vacuo and the product was purified by prep-TLC (33% EtOAc/ petroleum ether) to give N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-5-fluoro-4-h ydroxy- 3,4-dihydro-2,6-naphthyridine-2(1H)-carboxamide 27b as a colourless oil. LCMS (Method 5) m/z 407.9 (M+H) ⁺ (ES ⁺ ), at 1.98 min. Step 3: To a solution of N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-5-fluoro-4-h ydroxy- 3,4-dihydro-2,6-naphthyridine-2(1H)-carboxamide 27b (52 mg, 0.12 mmol) in DCM (5 ml) was added DAST (123 mg, 0.76 mol) at -78 °C. The reaction mixture was allowed to warm to RT and stirred for 30 min and then basified with saturated aqueous NaHCO ₃ solution and extracted with DCM (3 x 10 ml). The combined organics were dried over Na ₂ SO ₄ and concentrated in vacuo. The product was purified by prep-TLC (33% EtOAc/ petroleum ether) to give N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-4,5-difluoro -3,4-dihydro-2,6- naphthyridine-2(1H)-carboxamide 27 as a yellow solid. LCMS (Method 3) m/z 409.9 (M+H) ⁺ (ES ⁺ ), at 3.31 min; ¹ H NMR (400 MHz, DMSO-d6) δ 9.08 (s, 1H), 8.25 (d, J = 6.4 Hz, 1H), 7.91 (d, J = 6.8 Hz, 1H), 7.80 (d, J = 10.8 Hz, 1H), 7.36 (d, J = 5.2 Hz, 1H), 5.86 (d, J = 49.6 Hz, 1H), 5.27 (d, J = 20.4 Hz, 1H), 4.72 (t, J = 14.8 Hz, 1H), 4.43 (dd, J = 5.6 Hz, J = 18 Hz, 1H), 3.58 – 3.45 (m, 1H). Separation of enantiomers by chiral chromatography It will be appreciated that the enantiomers of the compounds described above can be isolated using techniques well known in the art, including, but not limited to, chiral chromatography. For example, a racemic mixture can be dissolved in a solvent, for example, methanol, followed by separation by chiral SFC on a Sepiatec with UV detection by DAD at 220 nm, 40 °C, 120 bar on a Chiralpak® IH (Daicel Ltd.) column (1 x 25 cm, 5 µm particle size), flow rate 20 ml/ min-1 using 40 % methanol to afford both enantiomers as the separated pure compounds. For example, (±)-(S)-N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-4-m ethyl-6-oxo-3,4,6,7- tetrahydro-2,7-naphthyridine-2(1H)-carboxamide (compound 21) was dissolved to 38 mg/ml in MeOH with sonication, filtered and was then separated by chiral SFC on a sepiatec with UV detection by DAD at 220 nm, 40 °C, 120 bar. The column was ChiralpakIH 10 x 250 mm, 5 ^m, flow rate 20 ml/min at 40 % MeOH, 60 % CO ₂ to afford (S)-N-(5-chloro-2-fluoro- 4-(trifluoromethyl)phenyl)-4-methyl-6-oxo-3,4,6,7-tetrahydro -2,7-naphthyridine-2(1H)- carboxamide (compound 25) and (R)-N-(5-chloro-2-fluoro-4-(trifluoromethyl)phenyl)-4- methyl-6-oxo-3,4,6,7-tetrahydro-2,7-naphthyridine-2(1H)-carb oxamide (compound 26) both as colourless solids. LCMS and NMR data for compounds 25 and 26 are found in the table below. The following compounds were prepared using appropriate starting materials in an analogous procedure to that described for 25 and 26.

Key: (a) stereochemistry arbitrarily assigned, ^(b) purified on Sepiatec prep SFC 50, ^(c) purified on Waters prep 15, ^(d) purified with a Chiralpak IG 10 x 250 mm, 5 ^m particle size column, ^(e) purified with a Chiralpak IH 10 x 250 mm, 5 ^m particle size column, SFC method 1- Chiralpak IG 4.6 x 250 mm, 5 ^m particle size, flow rate 4 ml/min SFC method 2- Chiralpak IH 4.6 x 250 mm, 5 ^m particle size, flow rate 4 ml/min Human GPR65 cyclic adenosine monophosphate (cAMP) Homogeneous Time Resolved Fluorescence (HTRF) antagonist assay procedure IC ₅₀ data was obtained by the following procedure: 1321N1 human astrocytoma cells stably expressing human recombinant GPR65 (1321N1- hrGPR65 cells, EuroscreenFast) were cultured according to the vendor’s instructions. Compounds were tested for their ability to antagonise GPR65, through measuring the concentration of cytoplasmic cAMP following treatment of the cells at a pH of 7.2 to activate GPR65 signalling and addition of the compound to be tested. The extent to which the expected rise in cAMP concentration upon GPR65 activation was suppressed by the added compound is indicative of its potency. The assay was carried out according to EuroscreenFast assay Methodology as follows. On the day of the assay, test compounds were added to 384-well, low volume, white microtiter plates by acoustic dispensing. KRH buffer (5 mM KCl, 1.25 mM MgSO ₄ , 124 mM NaCl, 25 mM HEPES, 13.3 mM Glucose, 1.25 mM KH ₂ PO ₄ and 1.45 mM CaCl ₂ ) was adjusted to pH 6.5, pH 7.6 and pH 8.4 by adding NaOH.1321N1-hGPR65 cells were rapidly thawed and diluted in KRH, pH 7.6 prior to centrifugation at 300 xg for 5 min and resuspension in assay buffer (KRH, pH 7.6, supplemented with 1 mM 3-isobutyl-1- methylxanthine (IBMX) and 200 µM ethylenediaminetetraacetic acid (EDTA)). Cells were added to assay plates at a density of 2,000 cells per well in a volume of 5 µl. Assay plates were briefly centrifuged at 100 xg and then incubated at room temperature for 30 min. Cells were stimulated by the addition of 5 µL KRH, pH 6.5, to achieve an assay pH of 7.2, while control wells received 5 µl KRH, pH 8.4 to achieve an assay pH of 7.9. Assay plates were briefly centrifuged at 100 xg and then incubated at room temperature for 30 min. Accumulation of cAMP was detected by cAMP HTRF kit (Cisbio). d2-labeled cAMP and cryptate-labeled anti-cAMP antibody in Lysis and Detection Buffer (Cisbio) were added to assay plates, and the plates were incubated at room temperature for 1 h. HTRF measurements were performed using a Pherastar FSX instrument. Acceptor and donor emission signals were measured at 665 nm and 620 nm, respectively, and HTRF ratios were calculated as signal _{665 nm} /signal _620nm x 10 ⁴ . Data were normalised to high and low control values and fitted with 4-parameter logistic regression to determine hGPR65 IC50 values for the test compounds, which are shown in Table 1. Various modifications and variations of the described aspects of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes of carrying out the invention which are obvious to those skilled in the relevant fields are intended to be within the scope of the following claims.

Table 1: Activity of selected compounds according to the invention High = IC ₅₀ < 500 nM; Medium = IC ₅₀ > 500 nM and < 5 μM; Low > 5 μM  

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