BICYCLIC PYRIMIDINE DERIVATIVES AS CALCIUM CHANNEL BLOCKERS

Technical Field

[0001] The invention relates to compounds useful in treating conditions associated with calcium channel function, and particularly conditions associated with T-type calcium channel activity. More specifically, the invention concerns compounds containing either thienopyrimidine or oxoquinazoline derivatives that are useful in treatment of conditions such as cardiovascular disease, epilepsy and pain.

Background Art

[0002] The entry of calcium into cells through voltage-gated calcium channels mediates a wide variety of cellular and physiological responses, including excitation-contraction coupling, hormone secretion and gene expression (Miller, RJ. , Science (1987) 235:46-52; Augustine, GJ. et al., Annu Rev Neurosci (1987) 10: 633-693). hi neurons, calcium channels directly affect membrane potential and contribute to electrical properties such as excitability, repetitive firing patterns and pacemaker activity. Calcium entry further affects neuronal functions by directly regulating calcium-dependent ion channels and modulating the activity of calcium-dependent enzymes such as protein kinase C and calmodulin-dependent protein kinase II. An increase in calcium concentration at the presynaptic nerve terminal triggers the release of neurotransmitter, which also affects neurite outgrowth and growth cone migration in developing neurons.

[0003] Calcium channels mediate a variety of normal physiological functions, and are also implicated in a number of human disorders. Examples of calcium-mediated human disorders include but are not limited to congenital migraine, cerebellar ataxia, angina, epilepsy, hypertension, ischemia, and some arrhythmias. The clinical treatment of some of these disorders has been aided by the development of therapeutic calcium channel antagonists (e.g., dihydropyridines, phenylalkyl amines, and benzothiazapines all target L-type calcium channels) (Janis, RJ. & Triggle, DJ. , In Calcium Channels: Their Properties, Functions, Regulation and Clinical Relevance (1991) CRC Press, London).

[0004] Native calcium channels have been classified by their electrophysiological and pharmacological properties into T-, L-, N-, P/ Q- and R- types (reviewed in Catterall, W., Annu Rev Cell Dev Biol (2000) 16: 521-555; Huguenard, J .R., Annu Rev Physiol (1996) 58:

329-348). T-type (or low voltage-activated) channels describe a broad class of molecules that transiently activate at negative potentials and are highly sensitive to changes in resting potential.

[0005] The L-, N- and P/Q-type channels activate at more positive potentials (high voltage-activated) and display diverse kinetics and voltage-dependent properties (Catterall (2000); Huguenard (1996)). T-type channels can be distinguished by having a more negative range of activation and inactivation, rapid inactivation, slow deactivation, and smaller single-channel conductances. There are three subtypes of T-type calcium channels that have been molecularly, pharmacologically, and electrophysiologically identified: these subtypes have been termed OC _{I G} , O-IH, and an (alternately called Cav 3.1, Cav 3.2 and Cav 3.3 respectively).

[0006] T-type calcium channels are involved in various medical conditions. In mice lacking the gene expressing the otiG subunit, resistance to absence seizures was observed (Kim, C. et al, MoI CellNeurosci (2001) 18(2): 235-245). Other studies have also implicated the αi _H subunit in the development of epilepsy (Su, H. et al., JNeurosci (2002) 22: 3645-3655). There is strong evidence that some existing anticonvulsant drugs, such as ethosuximide, function through the blockade of T-type channels (Gomora, J.C. et al, MoI Pharmacol (2001) 60: 1121-1132).

[0007] Low voltage-activated calcium channels are highly expressed in tissues of the cardiovascular system. Mibefradil, a calcium channel blocker 10-30 fold selective for T-type over L-type channels, was approved for use in hypertension and angina. It was withdrawn from the market shortly after launch due to interactions with other drugs (Heady, T.N., et al, Jpn J Pharmacol. (2001) 85:339-350).

[0008] Growing evidence suggests T-type calcium channels are also involved in pain (see for example: US Patent Application No. 2003/086980; PCT Palent Application Nos. WO 03/007953 and WO 04/000311). Both mibefradil and ethosuximide have shown anti-hyperalgesic activity in the spinal nerve ligation model of neuropathic pain in rats (Dogrul, A., et al, Pain (2003) 105:159-168). In addition to cardiovascular disease, epilepsy (see also US Patent Application No. 2006/025397), and chronic and acute pain, T- type calcium channels have been implicated in diabetes (US Patent Application No. 2003/125269), certain types of cancer such as prostate cancer (PCT Patent Application Nos. WO 05/086971 and WO 05/77082), sleep disorders (US Patent Application No. 2006/003985), Parkinson's disease (US Patent Application No. 2003/087799); psychosis

such as schizophrenia (US Patent Application No. 2003/087799), overactive bladder (Sui, G.-P., et al, British Journal of Urology International (2007) 99(2): 436-441; see also US 2004/197825) and male birth control.

[0009] All patents, patent applications and publications are herein incorporated by reference in their entirety.

Disclosure of the Invention

[0010] The invention relates to compounds useful in treating conditions modulated by calcium channel activity and in particular conditions mediated by T-type channel activity. The compounds of the invention are bicyclic pyrimidine derivatives with structural features that enhance the calcium channel blocking activity of the compounds. Thus, in one aspect, the invention is directed to a method of treating conditions mediated by calcium channel activity by administering to patients in need of such treatment at least one compound of formula (1) or formula (2):

or

or a pharmaceutically acceptable salt or conjugate thereof, wherein each Ri and R ₂ are independently, H, or an optionally substituted alkyl (1-6C), alkenyl (2-6C), alkynyl (2-6C), heteroalkyl (2-6C), heteroalkenyl (2-6C), heteroalkynyl (2- 6C), aryl (6-lOC), heteroaryl (5-12C), or C6-C12-aryl-Cl-C6-alkyl; or Ri and R ₂ together

with N to which they are attached form an optionally substituted 3-8 membered heterocyclic ring or 5-12 membered heteroaromatic ring; each R ₃ and R ₄ are independently H, halo or an optionally substituted alkyl (1-3C) or heteroalkyl (l-3C);

X is an optionally substituted alkylene (1-3C) or heteroalkylene (1-3C);

Y is Ar or N(R ₅ )(R ₆ ) wherein Ar is an optionally substituted aryl (6- 10C) or heteroaryl (5-12C) and R ₅ and R ₆ are independently, H, or an optionally substituted alkyl (1- 6C), alkenyl (2-6C), alkynyl (2-6C), heteroalkyl (2-6C), heteroalkenyl (2-6C), heteroalkynyl (2-6C), aryl (6- 10C), heteroaryl (5-12C), or C6-C12-aryl-Cl-C6-alkyl; or R ₅ and R ₆ together with N to which they are attached form an optionally substituted 3-8 membered heterocyclic ring or 5-12 membered heteroaromatic ring; wherein the optional substituents on each X, Ar, Ri, R ₂ , R ₃ , R ₄ and R ₅ are independently selected from halo, CN, NO ₂ , CF ₃ , OCF ₃ , COOR', CONR' ₂ , OR', SR', SOR', SO ₂ R', NR' ₂ , NR'(C0)R\ and NR ⁵ SO ₂ R', wherein each R' is independently H or an optionally substituted group selected from alkyl (1-6C), alkenyl (2-6C), alkynyl (2-6C), heteroalkyl (2-6C) heteroalkenyl (2-6C), and heteroalkynyl (2-6C); or the optional substituents maybe one or more optionally substituted groups selected from alkyl (1-6C), alkenyl (2-6C), alkynyl (2-6C), heteroalkyl (2-6C), heteroalkenyl (2-6C), or heteroalkynyl (2-6C); and wherein the optional substituent on X, R ¹ , R ² , R ⁵ and R ^fl may further be selected from =0 and =NOR'; and wherein optional substituents on a heterocyclic ring formed with R ¹ and R ² or R ⁵ and R ⁶ may independently be selected from =0, =N0R', halo, CN, NO ₂ , CF ₃ , OCF ₃ , COOR', CONR' ₂ , OR', SR', SOR', SO ₂ R', NR' ₂ , NR'(C0)R\ and NR'SO ₂ R', wherein each R' is independently H or an optionally substituted group selected from alkyl (1-6C), alkenyl (2-6C), alkynyl (2-6C), heteroalkyl (2-6C) heteroalkenyl (2-6), and heteroalkynyl (2- 6C); or the optional substituents may be one or more optionally substituted groups selected from alkyl (1-6C), alkenyl (2-6C), alkynyl (2-6C), heteroalkyl (2-6C), heteroalkenyl (2-6C), heteroalkynyl (2-6C), or aryl (6-1 OC), heteroaryl (5-12C), or C6-C12-aryl-Cl-C6-alkyl; with the provisos that for compounds of formula (1): when Y is N(R ₅ )(R ₆ ), a carbon atom in X or Y that is adjacent to the N in Y is substituted by =0; and when Y is Ar, then neither Rj nor R ₂ is arylalkyl.

[0011] The invention is also directed to the use of compounds of formula (1) and formula (2) for the preparation of medicaments for the treatment of conditions requiring

modulation of calcium channel activity, and in particular T-type calcium channel activity. In another aspect, the invention is directed to pharmaceutical compositions containing compounds of formula (1) and formula (2) and to the use of these compositions for treating conditions requiring modulation of calcium channel activity, and particularly T-type calcium channel activity. The invention is also directed to compounds of formula (1) and formula (2) useful to modulate calcium channel activity, particularly T-type channel activity.

Detailed Description

[0012] As used herein, the term "alkyl," "alkenyl" and "alkynyl" include straight-chain, branched-chain and cyclic monovalent substituents, as well as combinations of these, containing only C and H when unsubstituted. Examples include methyl, ethyl, isobutyl, cyclohexyl, cyclopentylethyl, 2-propenyl, 3-butynyl, and the like. Typically, the alkyl, alkenyl and alkynyl groups contain 1-8C (alkyl) or 2-8C (alkenyl or alkynyl). In some embodiments, they contain 1-6C, 1-4C, 1-3C or 1-2C (alkyl); or 2-6C, 2-4C or 2-3C (alkenyl or alkynyl). Further, any hydrogen atom on one of these groups can be replaced with a halogen atom, and in particular a fluoro or chloro, and still be within the scope of the definition of alkyl, alkenyl and alkynyl. For example, CF ₃ is a 1C alkyl. These groups may be also be substituted by other substituents.

[0013] Heteroalkyl, heteroalkenyl and heteroalkynyl are similarly defined and contain at least one carbon atom but also contain one or more O, S or N hetero atoms or combinations thereof within the backbone residue whereby each heteroatom in the heteroalkyl, heteroalkenyl or heteroalkynyl group replaces one carbon atom of the alkyl, alkenyl or alkynyl group to which the heteroform corresponds. In preferred embodiments, the heteroalkyl, heteroalkenyl and heteroalkynyl groups have C at each terminus to which the group is attached to other groups, and the heteroatom(s) present are not located at a terminal position. As is understood in the art, these heteroforms do not contain more than three contiguous heteroatoms. In preferred embodiments, the heteroatom is O or N. For greater certainty, to the extent that alkyl is defined as 1-6C, then the corresponding heteroalkyl contains 2-6 C, N, O, or S atoms such that the heteroalkyl contains at least one C atom and at least one heteroatom. Similarly, when alkyl is defined as 1-6C or 1-4C, the heteroform would be 2-6C or 2-4C respectively, wherein at least one C is replaced by O, N or S. Accordingly, when alkenyl or alkynyl is defined as 2-6C (or 2-4C), Ihen the corresponding heteroform would also contain 2-6 C, N, O, or S atoms (or 2-4) since the heteroalkenyl or

heteroalkynyl contains at least one carbon atom and at least one heteroatom. Further, heteroalkyl, heteroalkenyl or heteroalkynyl substituents may also contain one or more carbonyl groups. Examples of heteroalkyl, heteroalkenyl and heteroalkynyl groups include CH ₂ OCH ₃ , CH ₂ N(CH ₃ ) ₂ , CH ₂ OH, (CH ₂ ) _n NR ₂ , OR, COOR, CONR ₂ , (CH ₂ ) _n OR, (CH ₂ ) _n COR, (CH ₂ ) _π COOR, (CH ₂ ) _n SR, (CH ₂ ) _n SOR, (CH ₂ ) _n SO ₂ R, (CH ₂ ) _n CONR ₂ , NRCOR, NRCOOR, OCONR ₂ , OCOR and the like wherein the group contains at least one C and the size of the substituent is consistent with the definition of alkyl, alkenyl and alkynyl.

[0014] As used herein, the terms "alkylene," "alkenylene" and "alkynylene" refers to divalent groups having a specified size, typically 1-2C, 1-3C, 1-4C, 1-6C or 1-8C for the saturated groups and 2-3C, 2-4C, 2-6C or 2-8C for the unsaturated groups. They include straight-chain, branched-chain and cyclic foπns as well as combinations of these, containing only C and H when unsubstituted. Because they are divalent, they can link together two parts of a molecule, as exemplified by X in formula (1) and formula (2). Examples include methylene, ethylene, propylene, cyclopropan-l,l-diyl, ethylidene, 2--butene-l,4-diyl, and the like. These groups can be substituted by the groups typically suitable as substituents for alkyl, alkenyl and alkynyl groups as set forth herein. Thus C=O is a Cl alkylene that is substituted by =O, for example.

[0015] Heteroalkylene, heteroalkenylene and heteroalkynylene are similarly defined as divalent groups having a specified size, typically 2-3 C, 2-4C, 2-6C or 2-8C for the saturated groups and 2-3C, 2-4C, 2-6C or 2-8C for the unsaturated groups. They include straight chain, branched chain and cyclic groups as well as combinations of these, and they further contain at least one carbon atom but also contain one or more O, S or N heteroatoms or combinations thereof within the backbone residue, whereby each heteroatom in the heteroalkylene, heteroalkenylene or heteroalkynylene group replaces one carbon atom of the alkylene, alkenylene or alkynylene group to which the heteroform corresponds. As is understood in the art, these heteroforms do not contain more than three contiguous heteroatoms.

[0016] "Aromatic" moiety or "aryl" moiety refers to any monocyclic or fused ring bicyclic system which has the characteristics of aromaticity in terms of electron distribution throughout the ring system and includes a monocyclic or fused bicyclic moiety such as phenyl or naphthyl; "heteroaromatic" or "heteroaryl" also refers to such monocyclic or fused bicyclic ring systems containing one or more heteroatoms selected from O, S and N. The inclusion of a heteroatom permits inclusion of 5-membered rings to be considered aromatic

as well as 6-membered rings. Thus, typical aromatic/heteroaromatic systems include pyridyl, pyrimidyl, indolyl, benzimidazolyl, benzotriazolyl, isoquinolyl, quinolyl, benzothiazolyl, benzofuranyl, thienyl, fαryl, pyrrolyl, thiazolyl, oxazolyl, imidazolyl and the like. Because tautomers are theoretically possible, phthalimido is a! so considered aromatic. Typically, the ring systems contain 5-12 ring member atoms or 6-10 ring member atoms. In some embodiments, the aromatic or heteroaromatic moiety is a 6-membered aromatic rings system optionally containing 1-2 nitrogen atoms. More particularly, the moiety is an optionally substituted phenyl, 2-, 3- or 4-pyridyl, indolyl, 2- or 4- pyrimidyl, pyridazinyl, benzothiazolyl or benzimidazolyl. Even more particularly, such mciety is phenyl, pyridyl, or pyrimidyl and even more particularly, it is phenyl.

[0017] "O-aryl" or "O-heteroaryl" refers to aromatic or heteroaromatic systems which are coupled to another residue through an oxygen atom. A typical example of an O-aryl is phenoxy. Similarly, "arylalkyl" refers to aromatic and heteroaromatic systems which are coupled to another residue through a carbon chain, saturated or unsaturated, typically of 1- 8C, 1-6C or more particularly 1-4C or 1-3C when saturated or 2-8C, 2-6C, 2-4C or 2-3C when unsaturated, including the heteroforms thereof. For greater certainty, arylalkyl thus includes an aryl or heteroaryl group as defined above connected to an alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl or heteroalkynyl moiety also as defi tied above. Typical arylalkyls would be an aryl(6-12C)alkyl(l-8C), aryl(6-12C)alkenyl(2-8C), or aryl(6- 12C)alkynyl(2-8C), plus the heteroforms. A typical example is phenylmethyl, commonly referred to as benzyl.

[0018] Typical optional substituents on aromatic or heteroaromatic groups include independently halo, CN, NO ₂ , CF ₃ , OCF ₃ , COOR', CONR' ₂ , OR', SR', SOR', SO ₂ R', NR' ₂ , NR'(CO)R\NR'C(O)OR\ NR'C(0)NR' ₂ , NR'SO ₂ NR' ₂ , Or NR ⁵ SO ₂ R', wherein each R' is independently H or an optionally substituted group selected from alkyl, alkenyl, alkynyl, heteroaryl, and aryl (all as defined above); or the substituent may be an optionally substituted group selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, aryl, heteroaryl, O-aryl, O-heteroaryl and arylalkyl.

[0019] Optional substituents on a non-aromatic group, are typically selected from the same list of substituents suitable for aromatic or heteroaromatic groαps and may further be selected from =0 and =N0R' where R' is H or an optionally substituted group selected from alkyl, alkenyl, alkynyl, heteroaryl, and aryl (all as defined above).

[0020] Halo may be any halogen atom, especially F, Cl, Br, or 1, and more particularly it is fluoro, or chloro.

[0021] In general, any alkyl, alkenyl, alkynyl, or aryl (including, all heteroforms defined above) group contained in a substituent may itself optionally be substituted by additional substituents. The nature of these substituents is similar to those recited with regard to the substituents on the basic structures above. Thus, where an embodiment of a substituent is alkyl, this alkyl may optionally be substituted by the remaining substituents listed as substituents where this makes chemical sense, and where this does not undermine the size limit of alkyl per se; e.g., alkyl substituted by alkyl or by alkenyl would simply extend the upper limit of carbon atoms for these embodiments, and is not included. However, alkyl substituted by aryl, amino, halo and the like would be included.

[0022] X may independently be an optionally substituted alkylene or heteroalkylene (as defined above). In a more particular embodiment, X may independently be an optionally substituted ethylene or an optionally substituted methylene, and even more particularly, the optional substituent can be a carbonyl. In specific embodiments, X is CH ₂ C=O or CH ₂ CH ₂ or CH(CH ₃ )C=O or CH ₂ .

[0023] In some embodiments, Y in compounds of Formula (1) or (2) is an optionally substituted aryl moiety or an optionally substituted heteroaryl moiely. In more particular embodiments, Y is an optionally substituted phenyl ring. For example, Y may be unsubstituted phenyl or a halogenated phenyl such as 2-, 3- or 4-fluorophenyl and more particularly 2-fluorophenyl. In other embodiments, Y is N(R ₅ )(R ₆ ). In such embodiments, R ₅ and R ₆ may be the same or different and may independently by H, or an optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, aryl, heteroaryl or arylalkyl. In more particular embodiments, R ₅ and R ₆ are H or an optionally substituted alkyl or heteroalkyl and even more particularly R ₅ and R ₆ are H or an optionally substituted alkyl. For example, R ₅ and R ₆ may be H, or an optionally substituted methyl, ethyl, butyl, cyclohexyl, cyclopentyl, cyclopropyl, or phenyl. In particular embodiments, optional substituents include halo and methyl and trifluoromethyl. In other embodiments, R ₅ and R ₆ together with N in NR ₅ R ₆ may form an optionally substituted 3-8 membered heterocyclic ring or 5-12 membered heteroaromatic ring such as a pyrrolidinyl, piperidinyl, piperazinyl, morpholino or pyridinyl or pyrrolyl. In more particular embodiments, R ₅ and R ₆ together form an optionally substituted heterocyclic ring. Without limiting the generality of the

substituents as defined herein, examples of more particular substituents include halo, methyl, trifiuoromethyl, and =O as substituents on such heterocyclic ring.

[0024] Ri and R ₂ are independently H or an optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, aryl, heteroaryl or arylalkyl. In more particular embodiments, Ri and R ₂ are H or an optionally substituted alkyl, heteroalkyl, aryl or arylalkyl. Further, Ri and R ₂ may be the same or different. For example, Ri and R ₂ may independently be H or methyl, butyl, phenyl or benzyl. In other embodiments, Ri and R ₂ together form an optionally substituted 3-8 membered heterocyclic or 5-12 membered heteroaromatic ring such as a pyrrolidinyl, piperidinyl, piperazinyl, morpholino or pyridinyl or pyrrolyl. Without limiting the generality of the substituents defined herein, examples of even more particular substituents on such optionally substituted ring include halo, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, or arylalkyl. More specific examples of substituents on such a heterocyclic ring include fluoro, methyl, trifiuoromethyl, optionally substituted phenyl, benzyl, and morpholino. Even more specific examples include benzoyl, fluoro-benzoyl, phenyl, chlorophenyl, trifiuoromefiylphenyl, butylphenyl, methoxyphenyl, nitrophenyl, and methylphenyl.

[0025] Each R ₃ and R ₄ is independently H, halo or an optionallv substituted alkyl (1-3C) or heteroalkyl (1 -3C). In particular embodiments, R ₃ is H or methyl. In a more particular embodiment, R ₃ is methyl and the compound is of formula (1). In another embodiment R ₃ is H and the compound is of formula (2). In some embodiments, R ₄ is H.

[0026] In compounds of formula (2), the amide chain on the quinazolinone may be at the six position as shown in formula (3) or in the seven position as shown in formula (4):

or

(4)

[0027] In some preferred embodiments, two or more of the particularly described groups are combined into one compound: it is often suitable to combine one of the specified embodiments of one feature as described above with a specified embodiment or embodiments of one or more other features as described above. For example, a specified embodiment includes X being CH ₂ C=O, and another specified embodiment has Y is N(Rs)(R ₆ ) where R ₅ and R ₆ form a heterocyclic ring such as a piperidinyl. Thus one preferred embodiment combines both of these features together, i.e., X is CH ₂ C=O in combination with Y = NR ₅ R ₆ , where NR ₅ R ₆ is an optionally substituted piperidinyl. In some specific embodiments, R ₃ is H and in others R ₃ is methyl. Thus additional preferred embodiments include R ₃ as H in combination with any of the preferred combinations set forth above; other preferred combinations include R ₃ as methyl in combination with any of the preferred combinations set forth above.

[0028] The compounds of the invention may have ionizable groups so as to be capable of preparation as salts. These salts may be acid addition salts involving inorganic or organic acids or the salts may, in the case of acidic forms of the compounds of the invention be prepared from inorganic or organic bases. Frequently, the compounds are prepared or used as pharmaceutically acceptable salts prepared as addition products of pharmaceutically acceptable acids or bases. Suitable pharmaceutically acceptable acids and bases are well- known in the art, such as hydrochloric, sulphuric, hydrobromic, acelic, lactic, citric, or tartaric acids for forming acid addition salts, and potassium hydroxide, sodium hydroxide, ammonium hydroxide, caffeine, various amines, and the like for forming basic salts. Methods for preparation of the appropriate salts are well-established in the art.

[0029] In some cases, the compounds of the invention contain one or more chiral centers. The invention includes each of the isolated stereoisomeric forms as well as mixtures of stereoisomers in varying degrees of chiral purity, including racemic mixtures. It also encompasses the various diastereomers and tautomers that can be formed.

[0030] Compounds of formula (1) and formula (2) are also usefαl for the manufacture of a medicament useful to treat conditions characterized by undesired T-type calcium channel activities.

[0031] In addition, the compounds of the invention may be coupled through conjugation to substances designed to alter the pharmacokinetics, for targeting, or for other reasons. Thus, the invention further includes conjugates of these compounds. For example, polyethylene glycol is often coupled to substances to enhance half-life; the compounds may

be coupled to liposomes covalently or noncovalently or to other particulate carriers. They may also be coupled to targeting agents such as antibodies or peptidomimetics, often through linker moieties. Thus, the invention is also directed to the compounds of formula (1) and formula (2) when modified so as to be included in a conjugate of this type.

Modes of Carrying out the Invention

[0032] The compounds of formula (1) and formula (2) are useful in the methods of the invention and, while not bound by theory, are believed to exert their desirable effects through their ability to modulate the activity of calcium channels, pεtrticularly the activity of T-type calcium channels. This makes them useful for treatment of certain conditions where modulation of T-type calcium channels is desired, including: cardiovascular disease; epilepsy; diabetes; certain types of cancer such as prostate cancer; pain, including both chronic and acute pain; sleep disorders; Parkinson's disease; psychosis such as schizophrenia; overactive bladder and male birth control.

[0033] Cardiovascular disease as used herein includes but is not limited to hypertension, pulmonary hypertension, arrhythmia (such as atrial fibrillation and ventricular fibrillation), congestive heart failure, and angina pectoris.

[0034] Epilepsy as used herein includes but is not limited to partial seizures such as temporal lobe epilepsy, absence seizures, generalized seizures, and tonic/clonic seizures.

[0035] Acute pain as used herein includes but is not limited to nociceptive pain and postoperative pain. Chronic pain includes but is not limited by: peripheral neuropathic pain such as post-herpetic neuralgia, diabetic neuropathic pain, neuropathic cancer pain, failed back- surgery syndrome, trigeminal neuralgia, and phantom limb pain; central neuropathic pain such as multiple sclerosis related pain, Parkinson disease related pain, post-stroke pain, posttraumatic spinal cord injury pain, and pain in dementia; musculoskeletal pain such as osteo arthritic pain and fibromyalgia syndrome; inflammatory pain such as rheumatoid arthritis and endometriosis; headache such as migraine, cluster headache, tension headache syndrome, facial pain, headache caused by other diseases; visceral pain such as interstitial cystitis, irritable bowel syndrome and chronic pelvic pain syndrome:; and mixed pain such as lower back pain, neck and shoulder pain, burning mouth syndrome and complex regional pain syndrome.

[0036] For greater certainty, in treating osteoarthritic pain, joint mobility will also improve as the underlying chronic pain is reduced. Thus, use of compounds of the present

invention to treat osteoarthritic pain inherently includes use of such compounds to improve joint mobility in patients suffering from osteoarthritis.

[0037] It is known that calcium channel activity is involved in a multiplicity of disorders, and particular types of channels are associated with particular conditions. The association of T-type channels in conditions associated with neural transmission would indicate that compounds of the invention which target T-type receptors are most useful in these conditions. Many of the members of the genus of compounds of formula (1) and formula (2) exhibit high affinity for T-type channels. Thus, as described below, they are screened for their ability to interact with T-type channels as an initial indication of desirable function. It is particularly desirable that the compounds exhibit IC ₅₀ values of <1 μM. The IC ₅ o is the concentration which inhibits 50% of the calcium, barium or other permeant divalent cation flux at a particular applied potential.

[0038] In order to be maximally useful in treatment, it is also helpful to assess the side reactions which might occur. Thus, in addition to being able to modulate a particular calcium channel, it is desirable that the compound has very low activity with respect to the liERG K ⁺ channel which is expressed in the heart. Compounds that block this channel with high potency may cause reactions which are fatal. Thus, for a compound that modulates the calcium channel, it is preferred that the hERG K ⁺ channel is not inhibited. Similarly, it would be undesirable for the compound to inhibit cytochrome p450 since this enzyme is required for drug detoxification. Finally, the compound will be evεiluated for calcium ion channel type specificity by comparing its activity among the various types of calcium channels, and specificity for one particular channel type is preferred. The compounds which progress through these tests successfully are then examined in animal models as actual drug candidates.

[0039] The compounds of the invention modulate the activity of calcium channels; in general, said modulation is the inhibition of the ability of the channel to transport calcium. As described below, the effect of a particular compound on calcium channel activity can readily be ascertained in a routine assay whereby the conditions are arranged so that the channel is activated, and the effect of the compound on this activation (either positive or negative) is assessed. Typical assays are described hereinbelow in Example 14.

Libraries and Screening

[0040] The compounds of the invention can be synthesized individually using methods known in the art per se, or as members of a combinatorial library.

[0041] Synthesis of combinatorial libraries is now commonplace in the art. Suitable descriptions of such syntheses are found, for example, in Wentworth, Jr., P., et al., Current Opinion in Biol. (1993) 9:109-115; Salemme, F. R., et al, Structure (1997) 5:319-324. The libraries contain compounds with various substituents and various degrees of unsaturation, as well as different chain lengths. The libraries, which contain, as few as 10, but typically several hundred members to several thousand members, may then be screened for compounds which are particularly effective against a specific subtype of calcium channel, e.g., the N-type channel. In addition, using standard screening protocols, the libraries may be screened for compounds that block additional channels or receptors such as sodium channels, potassium channels and the like.

[0042] Methods of performing these screening functions are well known in the art. These methods can also be used for individually ascertaining the ability of a compound to agonize or antagonize the channel. Typically, the channel to be targeted is expressed at the surface of a recombinant host cell such as human embryonic kidney cells. The ability of the members of the library to bind the channel to be tested is measured, for example, by the ability of the compound in the library to displace a labeled binding ligand such as the ligand normally associated with the channel or an antibody to the channel. More typically, ability to antagonize the channel is measured in the presence of calcium, barium or other permeant divalent cation and the ability of the compound to interfere with the signal generated is measured using standard techniques. In more detail, one method involves the binding of radiolabeled agents that interact with the calcium channel and subsequent analysis of equilibrium binding measurements including, but not limited to, on rates, off rates, K _d values and competitive binding by other molecules.

[0043] Another method involves the screening for the effects of compounds by electrophysiological assay whereby individual cells are impaled with a microelectrode and currents through the calcium channel are recorded before and after application of the compound of interest.

[0044] Another method, high-throughput spectrophotometric assay, utilizes loading of the cell lines with a fluorescent dye sensitive to intracellular calcium concentration and

subsequent examination of the effects of compounds on the ability of depolarization by potassium chloride or other means to alter intracellular calcium levels.

[0045] As described above, a more definitive assay can be used to distinguish inhibitors of calcium flow which operate as open channel blockers, as opposed to those that operate by promoting inactivation of the channel or as resting channel blockers. The methods to distinguish these types of inhibition are more particularly described in the examples below. In general, open-channel blockers are assessed by measuring the level of peak current when depolarization is imposed on a background resting potential of about -100 mV in the presence and absence of the candidate compound. Successful open-channel blockers will reduce the peak current observed and may accelerate the decay of this current. Compounds that are inactivated channel blockers are generally determined by their ability to shift the voltage dependence of inactivation towards more negative potentials. This is also reflected in their ability to reduce peak currents at more depolarized holding potentials (e.g. , -70 mV) and at higher frequencies of stimulation, e.g., 0.2 Hz vs. 0.03 Hz. Finally, resting channel blockers would diminish the peak current amplitude during the very first depolarization after drug application without additional inhibition during the depolarizcition.

[0046] Accordingly, a library of compounds of formula (1) and formula (2) can be used to identify a compound having a desired combination of activities that includes activity against at least one type of calcium channel. For example, the library can be used to identify a compound having a suitable level of activity on T-type calcium channels while having minimal activity on HERG K+ channels.

Utility and Administration

[0047] For use as treatment of human and animal subjects, the compounds of the invention can be formulated as pharmaceutical or veterinary compositions. Depending on the subject to be treated, the mode of administration, and the type of treatment desired — e.g., prevention, prophylaxis, therapy; the compounds are formulated in ways consonant with these parameters. A summary of such techniques is found in Remington's Pharmaceutical Sciences, latest edition, Mack Publishing Co., Easton, PA, incorporated herein by reference.

[0048] In general, for use in treatment, the compounds of formula (1) and formula (2) may be used alone, as mixtures of two or more compounds of formula (1) or formula (2) or in combination with other pharmaceuticals. An example of other potential pharmaceuticals

to combine with the compounds of formula (1) or formula (2) would include pharmaceuticals for the treatment of the same indication but having a different mechanism of action from T-type calcium channel blocking. For example, in the treatment of pain, a compound of formula (1) or formula (2) may be combined with another pain relief treatment such as an NSAID, or a compound which selectively inhibits COX-2, or an opioid, or an adjuvant analgesic such as an antidepressant. Another example of a potential pharmaceutical to combine with the compounds of formula (1) or formula (2) would include pharmaceuticals for the treatment of different yet associated or related symptoms or indications. Depending on the mode of administration, the compounds will be formulated into suitable compositions to permit facile delivery.

[0049] The compounds of the invention may be prepared and used as pharmaceutical compositions comprising an effective amount of at least one compound of formula (1) or formula (2) admixed with a pharmaceutically acceptable carrier or excipient, as is well known in the art. Formulations may be prepared in a manner suitab Ie for systemic administration or topical or local administration. Systemic formulations include those designed for injection (e.g., intramuscular, intravenous or subcutaneous injection) or may be prepared for transdermal, transmucosal, or oral administration. The formulation will generally include a diluent as well as, in some cases, adjuvants, buffers, preservatives and the like. The compounds can be administered also in liposomal compositions or as microemulsions.

[0050] For injection, formulations can be prepared in conventional forms as liquid solutions or suspensions or as solid forms suitable for solution or suspension in liquid prior to injection or as emulsions. Suitable excipients include, for example, water, saline, dextrose, glycerol and the like. Such compositions may also contain amounts of nontoxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like, such as, for example, sodium acetate, sorbitan monolaurate, and so forth.

[0051] Various sustained release systems for drugs have also been devised. See, for example, U.S. patent No. 5,624,677.

[0052] Systemic administration may also include relatively noninvasive methods such as the use of suppositories, transdermal patches, transmucosal delivery and intranasal administration. Oral administration is also suitable for compounds of the invention. Suitable foπns include syrups, capsules, tablets, as is understood in ihe art.

[0053] For administration to animal or human subjects, the dosage of the compounds of the invention is typically 0.01-15 mg/kg, preferably 0.1-10 mg/kg. However, dosage levels are highly dependent on the nature of the condition, drug efficacy, the condition of the patient, the judgment of the practitioner, and the frequency and mode of administration. Optimization of the dosage for a particular subject is within the ordinary level of skill in the art.

Synthesis of the Invention Compounds

[0054] The following reaction schemes and examples are intended to illustrate the synthesis of a representative number of compounds. Accordingly, the following examples are intended to illustrate but not to limit the invention. Additional compounds not specifically exemplified may be synthesized using conventional methods in combination with the methods described hereinbelow.

Example 1

Synthesis of 2-(6-(4-f3,4-dichlorophenyl)piperazine-l-carbonyl)-5-methyl- 4-oxothieno[2,3- d]pyrimidin-3(4H)-yl)-N,N-diethylacetamide (Compound 6)

A. Synthesis of methyl 3-(2-(diethylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihvdrothieno[2,3-d1pyrimidine-6-carboxylate

100551 To a suspension of methyl 5-methyl-4-oxo-3, 4-dihydrottiieno [2, 3-d] pyrimidine-6-carboxylate (2.24 g, 10 mmol) in CH ₃ CN (20 mL) was added K ₂ CO ₃ (1.38 g, 10 mmol), KI (1.61 g, 10 mmol), and 2-chloro-N,N-diethylacetamide (1.4 mL, 10 mmol). The reaction mixture was refluxed overnight and quenched with H ₂ O (50 mL). The resulting

precipitate was filtered and dried to afford 3.3 g of methyl 3-(2-(die1hylamino)-2-oxoethyl)- 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6-carboxyl ate as a solid (yield: quantitative).

B. Synthesis of 3-(2-(diethylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4-dihvdroth ieno[2,3- d]pyrimidine-6-carboxylic acid

[0056] To a solution of methyl 3-(2-(diethylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidine-6-carboxylate (3.3g, 10 mmol) in THF (30 mL), MeOH (10 mL), and H ₂ O (10 mL) was added lithium hydroxide monohydrate (1.26g, 30 mmol). The reaction mixture was then stirred at RT overnight. The reaction mixture was concentrated, diluted with H ₂ O (30 mL) and washed with DCM (2 x 30 mL). The aqueous layer was acidified (pH ~ 2) with IM HCl and the resultant precipitate was filtered and dried to give 1.6 g of 3-(2-(diethylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4-dihydroth ieno[2,3- d]pyrimidine-6-carboxylic acid, (yield: 50%).

C. Synthesis of 2-(6-(4-(3,4-dichloiOphenyl)piperazine-l-carbonyl)-5-methyl- 4- oxothieno[2,3-d]pyiimidin-3(4H)-yl)-N,N-diethylacetamide

[0057] To a mixture of 3-(2-(diethylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidine-6-carboxylic acid (0.12 g, 0.37 mmol) in DCM (5 mL) was added DIEA (0.2 mL, 1.1 mmol), 4(3,4-dichlorophenyl)piperazine (0.073 g, 0.37 mmol), and HATU (0.182 g, 0.48 mmol). The reaction mixture was stirred at RT overnight. The organic layer was diluted with CH ₂ Cl ₂ and then washed with sat. NaHCO ₃ aq. (20 mL), dried over Na ₂ SO ₄ , and concentrated to give crude product as a gummy solid. Purification by flash column chromatography using a mixture Of Et ₂ O: DCM (1 : 1) as the eluant afforded

the 0.092 g of 2-(6-(4-(3,4-dichlorophenyl)piperazine-l-carbonyl)-5-methyl- 4-oxo thieno[2,3-d]pyrimidin-3(4H)-yl)-N,N-diethylacetamide, (yield:50%).

Example 2

Synthesis of N-tert-butyl-2-(6-(4-(4-chlorophenvπpiperazine-l-carbonyl)- 5-methyl-4-oxo thieno[2,3-d]pyrimidin-3(4H)-yl)acetamide (Compound 15)

A. Synthesis of N-tert-butyl-2-chloroacetamide

[0058] To a cooled (0 ⁰ C) solution of tert-butyl amine (5.25 mL, 50 mmol) in DCM (40 mL) was added triethylamine (14 mL, 101 mmol) followed by chloro acetylchloride (3.98 mL, 50.3 mmol). The reaction was warmed to RT and stirred for 2h. The reaction mixture was concentrated, redissolved in EtOAc (20 mL) and washed with brine. The organic layer was dried over anhydrous Na ₂ SO4 and concentrated to yield 5.39 g of crude product which was further purified by flash column chromatography using 7:3 Pet. Ether: EtOAc as the eluant. Pure N-tert-butyl-2-chloroacetamide (3.65 g) was isolated.

B. Synthesis of methyl 3-(2-(tert-butylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihydrothieno | ^~ 2,3-d]pyrimidine-6-carboxylate

[0059] To a suspension of methyl 5-methyl-4-oxo-3, 4-dihydrothieno [2, 3-d] pyrimidine-6-carboxylate (2.69 g, 12 mmol) in CH ₃ CN (30 mL) was added K ₂ CO ₃ (2.01 g, 14.5 mmol), KI (2.0 g, 12 mmol), and N-tert-butyl-2-chloroacetamide (1.8 g, 12 mmol). The reaction mixture was refluxed overnight and quenched with H ₂ O (150 mL). The resulting

precipitate was filtered and dried to afford methyl 3-(2-(tert-butylamino)-2-oxoethyl)-5- methyl-4-oxo-3, 4-dihydrothieno [2,3-d] pyrimidine-6-carboxylate, as a solid (yield: quantitative).

C. Synthesis of 3-(2-(tert-butylamino)-2-oxoethyl)-5-methyl-4-oxo -3,4-dihvdrothieno[2,3- d] pyrimidine-6-carboxylic acid

[0060] To a solution of methyl 3-(2-(tert-butylamino)-2-oxoeth>l)-5-methyl-4-oxo-3, A- dihydrothieno [2,3-d] pyrimidine-6-carboxylate, (3.3 g, 10 mmol) in THF (30 mL), MeOH (10 mL), and H ₂ O (10 mL) was added lithium hydroxide monohydrate (1.26 g, 30 mmol). The reaction mixture was stirred at RT overnight. The reaction mixture was concentrated, diluted with H ₂ O (30 mL) and washed with DCM (2x 30 mL). The aqueous layer was acidified (pH ~ 2) with IM HCl and the resultant precipitate was filtered and dried to give 1.8 g of 3-(2-(tert-butylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4-dihydr othieno[2,3-d3 pyrimidine-6-carboxylic acid (yield: 55%).

D. Synthesis of N-tert-butyl-2-(6-(4-(4-chloiOphenyl)piperazine-l -carbonyl)-5-methyl-4- oxothieno [2,3-d] pyrimidin-3(4H)-yl)acetamide

[0061] To a solution of 3-(2-(tert-butylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihydrothieno[2,3-d] pyrimidine-6-carboxylic acid, (0.13 g, 0.4 mmol) in DCM (5 mL) was added DIEA (0.2 mL, 1.1 mmol), l-[4(chlorophenyl)] piperazine (0.107 g, 0.4 mmol), and HATU (0.197 g, 0.52 mmol). The reaction mixture was stirred at RT' overnight. The organic layer was washed with sat. NaHCO ₃ aq. (20 mL), dried over Na ₂ SO ₄ , and concentrated to give crude product as a gummy solid. Purification by flash column chromatography using a mixture Of Et ₂ O: DCM (1 :1) as the eluant afforded the 0.065 g of N-tert-butyl-2-(6-(4-(4-

chlorophenyl)piperazine-l -carbonyl)-5-methyl-4-oxothieno [2, 3-d] pyrimidin-3(4H)- yl)acetamide, (yield:40%).

Example 3

Synthesis of 2-(6-(4-(3-chlorophenvDpiperazine-l-carbonyl)-5-methyl-4-oxo thieno| ^" 2,3- d1pyrimidin-3(4H)-yl)-N-cyclohexylacetamide (Compound 24)

A. Synthesis of 2-chloro-N-cyclohexylacetamide

[0062] To a cooled (0 ⁰ C) solution of cyclohexylamine (2.31 mL, 20 mmol) in DCM (20 mL) was added tri ethyl amine (5.7 mL, 40 mmol) followed by chloro acetyl chloride (1.61 mL, 20 mmol). The reaction was warmed to RT and stirred for 3 h. The reaction mixture was concentrated, redissolved in EtOAc (20 mL) and washed with brine. The organic layer was dried over anhydrous Na ₂ SO ₄ and concentrated to yield crude product which was further purified by flash column chromatography using 7:3 Pet. Ether: EtOAc as the eluant. 1.8 g of pure 2-chloro-N-cyclohexylacetamide was isolated.

B. Synthesis of methyl 3-(2-(cyclohexylamino)-2-oxoethyl)-5-metbyl-4-oxo-3,4- dihydrothieno r2,3-d]pyrimidine-6-carboxylate

[0063] To a suspension of methyl 5-methyl-4-oxo-3, 4-dihydrothieno [2, 3-d] pyrimidine-6-carboxylate (2.24 g, 10 mmol) in CH ₃ CN (25 mL) was, added K ₂ CO ₃ (1.38 g, 10 mmol), KI (1.61 g, 10 mmol), and 2-chloro-N-cyclohexylacetamide (1.75 g, 10 mmol). The inaction mixture was refluxed overnight and quenched with H ₂ O (120 mL). The resulting precipitate was filtered and dried to afford methyl 3-(2-(cyclohexylamino)-2-

oxoethyl)-5-methyl-4-oxo-3,4-dihydrothieno [2,3-d]pyrimidine-6-carboxylate, as a solid (yield: quantitative).

C. Synthesis of 3-(2-(cvdohexylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihydrothieno[2,3-d1 pyrimidine-6-carboxylic acid

[0064] To a solution of methyl 3-(2-(cyclohexylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihydrothieno [2,3-d]pyrimidine-6-carboxylate (3.6 g, 10 mmol) in THF (30 mL), MeOH (10 mL), and H ₂ O (10 mL) was added lithium hydroxide monohydrate (1.26 g, 30 mmol). The reaction mixture was then stirred at RT overnight. The reaction mixture was concentrated, diluted with H ₂ O (30 mL) and washed with DCM (2 x 30 mL). The aqueous layer was acidified (pH ~ 2) with IM HCl and the resultant precipitate was filtered and dried to give 1.7 g of 3-(2-(cyclohexylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4-dihydr othieno[2,3- d] pyrimidine-6-carboxylic acid, (yield: 52%).

D. Synthesis of 2-(6-(4-(3-chlorophenyl ^* )piperazine- 1 -carbonyl)-5-methyl-4-oxothieno[23- dlpyrimidin-3(4H ^' )-yl)-N-cvclohexylacetamide

[0065] To a solution of 3-(2-(cyclohexylamino)-2-oxoethyl)-5-nethyl-4-oxo-3,4- dihydrothieno[2,3-d] pyrimidine-6-carboxylic acid, (0.15 g, 0.45 mmol) in DCM (5 mL) was added DIEA (0.3 mL, 1.3 mmol), 1-3 (chlorophenyl) piperazine (0.12Og, 0.45 mmol), and HATU (0.220 g, 0.58 mmol). The reaction mixture was stirred at RT overnight. The organic layer was washed with sat. NaHCO ₃ aq. (20 mL), dried over Na ₂ SO ₄ , and concentrated to give crude product as a gummy solid. Purification by flash column chromatography using a mixture Of Et ₂ O: DCM (1 :1) as the eluant afforded the 0.082 g of 2- (6-(4-(3-chlorophenyl) piperazine- 1 -carbonyl)-5-methyl-4-oxothieno[2,3-d]pyrimidin- 3(4H)-yl)-N-cyclohexylacetamide, (yield:33%).

Example 4

Synthesis of N-(3, 5-bis(trifluoromethyl)phenyl)-2-(6-(4-( ^' 2-fluorophenyl ^' )piperazine-l - carbonyl)-5-methyl-4-oxothieno[2 ₁ 3-d1pyrimidin-3(4H)-yl)acetamide (Compound 64)

A. Synthesis of N-O.S-bisfcrifluoromethvUphenyl^-criloroacetamide

[0066] To a solution of 3, 5-bis (trifluoromethyl) aniline (3.74 g, 16.3 mmol) in DCM (60 niL) was added chloroacetic acid (2.3 Ig, 24.4 mmol), EDC (5.0 g, 32.6 mmol) and DMAP (cat.). The reaction mixture was stirred at RT overnight. The contents were transferred to a separator/ funnel and DCM layer was washed with saturated NaHCO ₃ solution, dried over anhydrous Na ₂ SO ₄ . The crude product was purified by flash column chromatography using 3:1 Pet. EtherDCM in. Purified product was isolated as a white solid weighing 3.67 g (yield: 74%).

B. Synthesis of methyl 3-(2-(3,5-bis(trifluoromethyl)phenylamino ^' )-2-oxoethyl)-5-methyl-4- oxo-3 _n 4-dihydrothieno[2,3-d]pyrimidine-6-carboxylate

[0067] To a suspension of methyl 5-methyl-4-oxo-3, 4-dihydrothieno [2, 3-d] pyrimidine-6-carboxylate (1.62 g, 7.2 mmol) in CH ₃ CN (35 mL) was added K ₂ CO ₃ (1.0 g, 7.24 mmol), KI (1.2 g, 7.23 mmol), and N-(3,5-bis(trifluoromethyl)phenyl)-2- chloroacetamide 1 (2.2 g, 7.19 mmol). The reaction mixture was refluxed overnight and quenched with H ₂ O (100 mL). The resultant precipitate was filtered and dried to afford 3.33

g of methyl 3-(2-(3,5-bis(trifluoromethyl) phenylamino)-2-oxoethyl)-5-methyl-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidine-6-carboxylate, as a solid (yield: 90%).

C. Synthesis of 3-(2-(3,5-bis(trifluoromethyl)phenylamino)-2-oxoethyl)-5-met hyl-4-oxo- 3.4-dihydrothieno[2,3-d]pyrimidine-6-carboxylic acid

[0068] To a solution of methyl 3-(2-(3,5-bis(trifluoromethyl)phenylamino)-2-oxoethyl)- 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]ρyrimidine-6-carboxy late,(3.3 g, 6.75 mmol) in THF (30 mL), MeOH (10 mL), and H ₂ O (10 mL) was added lithium hydroxide monohydrate (1.42 g, 33.8 mmol). The reaction mixture was then stirred at RT overnight. The reaction mixture was concentrated, diluted with H ₂ O (30 mL) and washed with DCM (2 x 30 mL). The aqueous layer was acidified (pH ~ 2) with IM HCl and the resultant precipitate was filtered and dried to give 1.9 g of 3-(2-(3,5-bis(trifluoromethyl)phenylamino)-2-oxoethyl)- 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6-carboxyl ic acid, (yield: 59%).

D. Synthesis of N-(3,5-bis(trifluoromethyl)phenyl)-2-(6-(4-(2-fluorophenyl)p iperazine-l- carbonyπ-5-methyl-4-oxothieno[2,3-d]pyrimidin-3(4H ^' )-yl)acetamide

10069] To a solution of 3-(2-(3,5-bis(trifluoromethyl)phenylamino)-2-oxoethyl)-5- methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6-carboxylic acid (0.24 g, 0.5 mmol) in DCM (5 mL) was added DIEA (0.3 mL, 1.5 mmol), 2-fluorophenylpiperazine (0.060 mL, 0.5 mmol), and HATU (0.25 g, 0.65 mmol). The reaction mixture was stirred at RT overnight. The organic layer was washed with sat. NaHCO ₃ aq. (20 mL), dried over Na ₂ SO ₄ , and concentrated to give crude product as a gummy solid. Purification by flash column chromatography using a mixture Of Et ₂ O: DCM (1 :1) as the eluant afforded the 0.19 g of the

desired product N-(3,5-bis(trifluoromethyl)phenyl)-2-(6-(4-(2-fluorophenyl)p iperazine-l - carbonyl)-5-methyl-4-oxo thieno[2,3-d]pyrimidin-3(4H)-yl)acetamide, (yield:60%).

Example 5

Synthesis of 3-(2-(4.,4-difluoropiρeridin-l-yl)-2-oxoethyl)-5-methyl-6-( 4-phenylpiperaziiie- 1 -carbonvl^thienof 2,3-d1pyrimidin-4(3H)-one (Compound 30)

A. Synthesis of 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6-carboxyl ic acid

[0070] To a solution of ethyl 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrirnidine-6- carboxylate (1.0 g, 4.5 mmol) in THF (14 mL), MeOH (3 mL), and H ₂ O (3 mL) was added lithium hydroxide monohydrate (0.68 g, 16 mmol). The reaction mixture was stirred at RT overnight. The reaction mixture was concentrated, diluted with H ₂ O (20 mL) and washed with DCM (25 mL). The aqueous layer was acidified (pH ~ 2) with IM HCl and the resultant precipitate was filtered and dried to give 0.9 g of pure 5-methyl-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidine-6-carboxylic acid, (yield: 94%).

B. Synthesis of 5-methyl-6-(4-phenylpiperazine-l -carbonyl)thieno[2,3-d]pyrimidin-4(3H)- one

[0071] To a solution of 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]ρyrimidine-6- carboxylic acid, (0.42 g, 2 mmol) in 1 :1 DCM and DMF (10 mL) was added EDC (0.764 g, 4 mmol), DMAP (cat.) and 4-phenylpiperazine (0.324 g, 2 mmol). The reaction was stirred

at RT overnight and DCM was removed. The resultant residue was partitioned between EtOAc (50 mL) and H ₂ O (50 mL). The organic layer was dried over Na ₂ SO ₄ and concentrated to provide 0.4g 5-methyl-6-(4-phenylpiperazine-l-carbonyl)thieno[2,3- d]pyrimidin-4(3H)-one, (yield: 57%).

C. Synthesis of 2-(4,4-difluoropiperidin-l-yl)acetyl chloride

[0072] To a solution of 4,4-difluoropiperidine hydrochloride (1.44 g, 9 mmol) in DCM (15 mL) was added chloroacetic acid (0.94 g, 10 mmol), TEA (1.5 mL), EDC (3.82 g, 20 mmol) and DMAP (cat.). The reaction mixture was stirred at RT overnight. The contents were transferred to a separatory funnel and DCM layer was washed saturated NaHCO ₃ solution, dried over anhydrous Na ₂ SO ₄ . The crude product was purified by flash column chromatography using 3:1 Pet. EtherDCM in. 2-(4,4-difluoropiperidin-l-yl)acetyl chloride was isolated as a white solid weighing 1.57 g (yield: 88%).

D. Synthesis of 3-(2-(4,4-difluoropiperidin-l -yl)-2-oxoethyP-5-methyl-6-(4-phenyl piperazine- 1 -carbonyl)thieno[2,3-d]pyrimidin-4(3H)-one

[0073] To a suspension of 5-methyl-6-(4-phenylpiperazine-l -carbonyl)thieno[2,3- d]pyrimidin-4(3H)-one, (0.4 g, 1.13 mmol) in CH ₃ CN (5 mL) was added K ₂ CO ₃ (0.156 g, 1.13 mmol), KI (0.182 g, 1.13 mmol), and 2-(4,4-difluoropiperidin-l-yl)acetyl chloride (0.223 g, 1.13 mmol). The reaction mixture was refluxed overnight and then quenched with H ₂ O (20 mL). The resultant precipitate was filtered and dried to provide a crude solid which was purified by flash chromatography (Et ₂ O: DCM, 1 :1) providing 0.29 g of pure 3-(2-(4,4- difluoropiperidin-l-yl)-2-oxoethyl)-5-methyl-6-(4-phenyl piperazine- lcarbonyl)thieno[2,3- d]pyrimidin-4(3H)-one, (yield: 50%).

Example 6

Synthesis of N-(2λ-difluorophenyiy2-(6-(4-(2-fluorophenyl)piperazine-l-c arbonyl)-5- methyl-4-oxothieno[2,3-d]pyrimidin-3{4H)-vQacetamide (Compound 139)

A. Synthesis of 6-(4-(2-fluorophenyl)piperazine-l -carbonyl)-5-methylthieno[2,3- dlpyrimidin-4C3 HV one

[0074] To a solution of 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6- carboxylic acid, (2 g, 9.5 mmol) in DMF (20 mL) was added DIEA (5 mL, 28.5 mmol), 1- (2-fluorophenyl)piperazine (1.7 g, 9.5 mmol), and HATU (4.7 g, 12.3 mmol). The reaction mixture was stirred at RT overnight. The reaction mixture was diluted with EtOAc (60 mL) and the organic layer was washed successively with sat. NaHCO ₃ aq. (50 mL) and brine (50 mL). The organic layer was separated, dried over Na ₂ SO ₄ , and concentrated to give crude product as a gummy solid. Purification by flash column chromatography using EtOAc as the eluant afforded the 3.0 g of pure 6-(4-(2-fluorophenyl)piperazine-l-carbonyl)-5- methylthieno[2,3-d]pyrimidin-4(3H)-one, (yield:86%).

B. Synthesis of 2-chloro-N-(2,4-difluorophenyl)acetamide

[0075] To a cooled (0 ⁰ C) solution of 2,4-difluoroaniline, (1.5 g, 11.6 mmol) in DCM (50 mL) was added triethylamine (1.9 mL, 13.9 mmol) followed by 2-chloroacetyl chloride (1.0 mL, 12.8 mmol). The reaction was warmed to RT and stirred for 2h. The reaction

mixture was concentrated, redissolved in EtOAc (50 mL) and washed with brine (50 mL). The organic layer was dried over anhydrous Na ₂ SO ₄ and concentrated to yield 2.2 g of crude product which was further purified by flash column chromatography using 1 :1 EtOAc:hexanes as the eluent. 2.Og of 2-chloro-N-(2,4-difluorophenyl)acetamide, (yield: 84%) was isolated.

C. Synthesis of N-(2,4-difluorophenyl ^' )-2-(6-(4-(2-fluorophenyl)piperazine-l-carbonyl)-5- methyl-4-oxothieno[2,3-dlpyrimidin-3(4H)-yl)acetamide

[0076] To a suspension of 6-(4-(2-fluorophenyl)piperazine-l-carbonyl)-5- methylthieno[2,3-d]pyrimidin-4(3H)-one, (0.06g, 0.16 mmol) in CH ₃ CN (0.5 mL) was added K ₂ CO ₃ (22mg, 0.16 mmol), KI (29 mg, 0.17 mmol), and 2-chloro-N-(2,4- difluorophenyl)acetamide, (36 mg, 0.16 mmol). The reaction mixture was heated at 130 °C for 25 min in a microwave reactor. The reaction was quenched with H ₂ O (25 mL) and the aqueous layer was extracted with EtOAc (25 mL). The organic layer was washed with brine (25 mL), dried over Na ₂ SO ₄ and concentrated. The crude material was purified by flash chromatography (Et ₂ O: DCM, 1:1) providing 30 mg of pure N-(2,4-difluorophenyl)-2-(6-(4- (2-fluorophenyl)piperazine-l-carbonyl)-5-methyl-4-oxothieno[ 2,3-d]pyrimidin-3(4H)- yl)acetamide, (yield: 35%).

Example 7

Synthesis of 3-(2-(4-(3-chlorophenyl)piperazin-l-yl)-2-oxoethyl)-5-methyl -6-(pyrrolidine-l- carbonyl)thienor2,3-d1pyrimidin-4(3H)-one (Compound 119)

A. Synthesis of -metliyl-6-(pyrrolidine-l -carbonyl)thieno[2,3-dlpyrimidin-4(3H)-one

[0077] To a cooled (0 ⁰ C) solution of pure 5-methyl-4-oxo-3,4-dihydrothieno[2,3- d]pyrimidine-6-carboxylic acid, (0.1 g, 0.47 mmol) in DMF (5 mL) was added dropwise thionyl chloride (0.034 mL, 0.47 mmol). The reaction mixture was stirred at 0 ⁰ C for 15 min. Pyrrolidine (0.12 mL, 1.4 mmol) was then added and the reaction was allowed to warm to RT over 1 h. The reaction mixture was quenched with saturated NaHCO ₃ (25 mL) and extracted with EtOAc (25 mL). The organic layer was washed with brine (30 mL), dried over Na ₂ SO ₄ and concentrated to give 0.080 g of pure 5-methyl-6-(pyrrolidine-l- carbonyl)thieno[2,3-d]ρyrimidin-4(3H)-one, (yield: 65%).

B. Synthesis of 2-chloro- 1 -(4-(3 -chlorophenyDpiperazin- 1 -vDethanone

[0078] To solution of l-(3-chlorophenyl)ρiperazine hydrochloride (1.2 g, 5.2 mmol) in DCM (10 mL) was added triethylamine (1.0 mL, 7.3 mmol), EDC (1.9 g, 10 mmol), DMAP (cat.) and chloroacetic acid (0.4 g, 5.2 mmol). The reaction was stirred at RT overnight and DCM was removed. The resultant residue was partitioned between EtOAc (50 mL) and H ₂ O (50 mL). The organic layer was dried over Na ₂ SO ₄ and concentrated to provide 1.Og of pure 2-chloro- l-(4-(3-chlorophenyl)piperazin-l-yl)ethanone, (yield: 70%).

C. Synthesis of 3-(2-(4-(3-chlorophenvDpiperazin-l-yl)-2-oxoethyl)-5-methyl- 6- (pyiτolidine-l-carbonyl)thieno[2,3-dlpyrimidin-4(3H)-one

[0079] To a suspension of 5-methyl-6-(pyiτolidine-l -carbonyl)thieno[2,3-d]pyrimidin- 4(3H)-one, (0.06 g, 0.23 mmol) in CH ₃ CN (5 mL) was added K ₂ CO ₃ (0.032 g, 0.23 mmol), KI (38 mg, 0.23 mmol), and 2-chloro-l-(4-(3-chlorophenyl)piperazin-l-yl)ethanone, (0.062

g, 0.23 mmol). The reaction mixture was refluxed overnight and then quenched with H ₂ O (20 mL). The resultant precipitate was filtered and dried to provide a crude solid which was purified by flash chromatography (Et ₂ O: DCM, 1 : 1 ) providing 0.025 g of pure 3-(2-(4-(3- chlorophenyl)ρiperazin- 1 -yl)-2-oxoethyl)-5-methyl-6-(pyrrolidine- 1 -carbonyl)thieno[2,3- d]pyrimidin-4(3H)-one, (yield: 22%).

Example 8

Synthesis of 2-(6-(4-(3-chlorophenvDpiρerazine-l -carbonyl)-5-methyl-4-oxothieno[2,3- dlpyrimidin-3(4H)-yl)-N-ethyl-N-(2.2.2-trifluoroethvπacetam ide (Compound 126)

A. Synthesis of 6-(4-(3-chlorophenyl)piperazine-l-carbonyl ^' )-5-methylthieno[2, 3- d]pyrimidin-4(3H)-one

[0080] To a solution of 5-methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6- carboxylic acid, (2 g, 9.5 mmol) in DMF (20 mL) was added DIEA (5 mL, 28.5 mmol), 1- (3-chlorophenyl) piperazine hydrochloride (2.2 g, 9.5 mmol), and HATU (4.7 g, 12.3 mmol). The reaction mixture was stirred at RT overnight. The reaction mixture was diluted with EtOAc (60 mL) and the organic layer was washed successively with sat. NaHCO ₃ aq. (50 mL) and brine (50 mL). The organic layer was separated, dried over Na ₂ SO ₄ , and concentrated to give crude product as a gummy solid. Purification by flash column chromatography using EtOAc as the eluent afforded the 3 g of pure 6-(4-(3-

chlorophenyl)piperazine-l-carbonyl)-5-methylthieno[2,3-d] pyrimidin-4(3H)-one, (yield: 81%).

B. Synthesis of N-ethyl-2,2,2-trifluoroethanamine hydrochloride

[0081] To a solution of 2,2,2-trifluoroethylamine hydrochloride (0.5 g, 3.7 mmol) in MeOH (5 niL) was added triethylamine (0.51 mL, 0.37 mmol) followed by acetaldehyde (1.0 mL, excess). The reaction mixture was then stirred at 0 ⁰ C for 3 h. Sodium borohydride (1 g, 5.9 mmol) was then added and the reaction mixture was stirred at 0 ⁰ C for 20 min. The reaction was quenched with IM NaOH (10 mL) and the aqueous layer was extracted with DCM (25 mL). The organic layer was separated and to it was added 2M HCl in Et ₂ O (10 mL). The resultant precipitate was filtered to give 0.45 g of N-ethyl-2,2,2- trifluoroethanamine hydrochloride, (yield: 75%).

C. Synthesis of 2-chloro-N-ethyl-N-(2.2.2-trifluoroethyl) acetamide

[0082] To a cooled (0 ⁰ C) solution of N-ethyl-2,2,2-trifluoroethanamine hydrochloride, (0.45 g, 2.8 mmol) in DCM (10 mL) was added triethylamine (1.6 mL, 11.2 mmol) followed by 2-chloroacetyl chloride (0.22 mL, 2.8 mmol). The reaction was warmed to RT and stirred for 2h. The reaction mixture was concentrated, redissolved in EtOAc (20 mL) and washed with brine (25 mL). The organic layer was dried over anhydrous Na ₂ SO ₄ and concentrated to yield 0.6 g of crude product which was further purified by flash column chromatography using 1 :1 EtOAσ.hexanes as the eluent. 0.5 g of 2-chloro-N-ethyl-N-(2,2,2- trifluoroethyl)acetamide, (yield: 88%) was isolated.

D. Synthesis of 2-(6-(4-(3-chlorophenyl)piperazine-l -carbonylV5-methyl-4-oxothieno[2,3- dlpyrimidin-3(4H)-yl)-N-ethyl-N-(2,2.2-trifluoroethyl)acetam ide

[0083] To a suspension of 6-(4-(3-chlorophenyl)piperazine-l-carbonyl)-5- methylthieno[2,3-d]pyrimidin-4(3H)-one, (0.1 g, 0.26 mmol) in CH ₃ CN (5 mL) was added K ₂ CO ₃ (36 mg, 0.26 mmol), KI (43 mg, 0.26 mmol), and 2-chloro-N-ethyl-N-(2,2,2- trifluoroethyl)acetamide, (52mg, 0.26 mmol). The reaction mixture was refluxed overnight and then quenched with H ₂ O (20 mL). The resultant precipitate was filtered and dried to provide a crude solid which was purified by flash chromatography (Et ₂ O: DCM, 1 :1) providing 30 mg of pure 2-(6-(4-(3-chlorophenyl)piperazine-l-carbonyl)-5-methyl-4- oxothieno[2,3-d]pyrimidin-3(4H)-yl)-N-ethyl-N-(2,2,2-trifluo roethyl)acetamide, (yield: 21%).

Example 9

Synthesis of Synthesis of 7-(4-(3-chlorophenyl) piperazine-1 Carbonyl)-3-(2-oxo-2-(- pyrrolidin-1-yl) ethyl) quinazolin-4(3H)-one (Compound 111)

A. Synthesis of 2-Aminoterephthalic acid

[0084] 3-Amino-4-(methoxylcarbonyl) benzoic acid (2.5 g, 12.8 mmol) was dissolved in a mixture of THF-MeOH -H ₂ O (4OmL, 30: 5: 5) and then LiOH- H ₂ O (2 g, 64 mmol) was added. The mixture stirred at RT over night. The reaction mixture was concentrated and the

residue was dissolved in 5 niL of water and then acidified with 6N HCl to pH~3. The solid was filtered and dried to give the desired product in 63% yield.

B. Synthesis of 4-Oxo-3, 4-dihvdroquinazoline-7-carboxylic acid

[0085] A mixture of 2-amino terephthalic acid (2 g, 11 mmol) and formamide (10 mL) was heated at 180 ⁰ C for 5 h. The reaction mixture was cooled to RT and acetone was added. The solid precipitated thus obtained was stirred for 2 h, filtered and dried to give 4-oxo-3, 4- dihydroquinazoline-7-carboxylic acid in 80% yield.

C. Synthesis of Methyl 4-oxo-3, 4-dihydroquinazoline-7-carboylate

[0086] A mixture of 4-oxo-3,4-dihydroquinazoline-7-carboxylic acid (2.5 g, 13.15 mmol) in 80 mL of methanol was added thionyl chloride (2.5 mL ) at 5 ⁰ C and then refluxed at 80 ⁰ C over night. The reaction mixture was concentrated under vacuum and the residue dissolved in ethyl acetate. The organic layer was washed with 10% aqueous NaHCO ₃ , water, brine and dried. The solvent was removed to give methyl 4-oxo-3, 4-dihydroquinazoline7- carboxylate in 70% yield as solid.

D. Synthesis of methyl 4-oxo-3-(2-oxo-2-(pyrrolidin-l-yl) ethyl-3, 4-dihydroquinazoline-7- carboxylate

[0087] Methyl 4-oxo-3,4-dihydroquinazoline-7-caboxylate (50 mg, 0.23 mmol) dissolved in of acetonitrile (15 mL) and then K ₂ CO ₃ (20 mg) , KI (15 mg) was added followed by addition of 2-chloro-l-( pyrroldin-1-yl ) ethanone (35 mg, 0.24 mmol).The mixture was refluxed over night. The reaction mixture was concentrated and the residue was

purified by flash chromatography (Et ₂ O: DCM, 1 :1) to give methyl 4-oxo-3-(2-oxo- 2(pyrroldin-l-yl) ethyl-3, 4-dihydroquinazoline-7-carboxlate in 70% yield.

E. Synthesis of 4-oxo-3-(2-oxo-2-(pyrrolidin-l-yl) ethyl-3, 4-dihvdroquinazoline-7- caboxylic acid

[0088] Methyl 4-oxo-3-(2-oxo-2-(pyrrolidin- 1 -yl)ethyl-3 ,4-dihydroquinazoline-7- carboxylate (lOOmg, 0.32 mmol) was dissolved in a mixture OfTHF-MeOH-H ₂ O (12mL, 10:1:1) followed by addition Of LiOH-H ₂ O (53 mg). The mixture was stirred at RT over night. The solvent evaporated and the residue was dissolved in water (2mL) and then acidified with 2N HCl to pH~3.The solid was filtered off and dried and gave 50 mg of acid in 60% yield.

F. Synthesis of 7-(4-(3-chlorophenyl) piρerazine-1 -carbonyD-3-(2-oxo-2-(pyrrolidin-l -yl) ethyl) quinazolin^QHVone

[0089] 4-oxo-3-(2-oxo-2-(pyrrolidin-l -yl)ethyl-3,4-dihydroquinazoline7-carboxylic acid (40 mg, 0.13 mmol) was dissolved in DCM (10 mL) followed by addition of DIEA (0.2 niL) HATU (100 mg) and 3-chlorophenyl piperazine (29 mg, 0.14 mmol).The mixture stirred at RT over night. The reaction mixture was concentrated and the residue was semi- purified by flash chromatography and then further purified by rotary prep TLC using DCM- Ether (1 :1) to give 7-(4-(3-chlorophenyl) piperazine-l-carbonyl)-3-(2-oxo-2-(pyrrolidin-l- yl) ethyl) quinazolin-4(3H)-one in 40% yield with the HPLC purity of > 95%.

Example 10

Synthesis of 6-(4-(3-chlorophenyl) piperazine-1 -carbonylV3-f2-oxo-2-(pyrrolidin-l -yl) ethyl) quinazolin-4(3H)-one (Compound 115 ^" )

A. Synthesis of 4-Nitro isophthalic acid

[0090] A mixture of 3-methyl-4-nitrobenzoic acid (6.3 g, 34.8 mmol), pyridine (100 mL) and water (10OmL) was heated to reflux. To the hot reaction mixture was added KMnO ₄ (130 g) portion wise and refluxed for 72 h. The reaction mixture was filtered through celite and washed with hot water. The filtrate was concentrated under vacuum, residue diluted with water (50 mL) and acidified with concentrated HCl at 0°C.The solid obtained was filtered, washed with water and dried under vacuum to give 4-nitro isophthalic acid in 40% yield.

B. Synthesis of 4- Amino isophthalic acid

[0091] To a solution of 4-nitro isophthalic acid (4 g, 18.95 mmol) in MeOH (200 mL) was added Pd/C (20%) and the mixture was hydrogenated at RT over night. The reaction mixture was filtered through Celite and filtrate concentrated under vacuum to give 4-amino isophthalic acid in 60% as a solid.

C. Synthesis of 4-Oxo-3, 4-dihydroquinazolin-6-carboxylic acid

[0092] A mixture of 4-amino isophthalic acid (2 g, 11.04 mmol) and formamide (10 niL) was heated at 180°C for 5 h. The reaction mixture was cooled to RT and acetone was added. The solid precipitate thus obtained was stirred for 2 h, filtered and dried to give 4-oxo-3, 4- dihydroquinazoline-6-carboxylic acid in 50% yield.

D. Synthesis of Methyl 4-Oxo-3, 4-dihydroquinazoline-6- carboxylate

[0093] To a mixture of 4-oxo-3,4-dihydroquinazoline-6-carboxylic acid (2.5 g, 13.15 mmol) in methanol (80 mL) was added thionyl chloride (2.5 mL) at 5°C. The mixture was refluxed at 80 ⁰ C over night. The reaction mixture was concentrated under vacuum and crude taken in ethyl acetate. The organic layer was washed with 10% aqueous NaHCO ₃ , water, brine and dried. The solvent was removed to give methyl 4-oxo-3,4-dihydroquinazoline-6- carboxylate in 55% as solid.

E. Synthesis of methyl 4-oxo-3-(2-oxo-2-(pyrrolidin-l-vQ ethyl-3, 4-dihydroquinazoline-6- carboxylate

[0094] Methyl 4-oxo-3,4-dihydroquinazoline-6-caboxylate (50 mg), dissolved in acetonitrile (15 mL) and then K ₂ CO ₃ (20 mg) KI (15 mg) was added followed by addition of 2-chloro-l-(pyrroldin-l-yl) ethanone (35mg, 0.23 mmol).The mixture was refluxed over night. The resulting mixture was evaporated followed by purification using flash chromatography (Et ₂ O: DCM, 1 :1) to give methyl 4-oxo-3-(2-oxo-2(pyiτoldin-l-yl))ethyl- 3,4-dihydroquinazoline-6-carboxlate in 70% yield.

F. Synthesis of 4-oxo-3-(2-oxo-2-(pyrroh ^' din-l -yl) ethyl-3, 4-dihydroquinazolme-6- caboxylic acid

[0095] Methyl 4-oxo-3-(2-oxo-2-(pyrrolidin-l-yl) ethyl-3,4-dihydroquinazoline-6- carboxylate (100 mg, 0.31 mmol) was dissolved in a mixture OfTHF-MeOH-H ₂ O (12mL, 10:1 :1) followed by the addition of LiOH-H ₂ O (53 mg). The mixture was stirred at RT over night. The solvent evaporated and the residue was dissolved in 2 mL of water and then acidified with 2N HCl to pH~3.The solid was filtered off and dried and gave 50 mg of acid in 60% yield.

G. Synthesis of 6-(4-(3-chlorophenvπ piperazine-l-carbonyl)-3-(2-oxo-2-(pyrrolidin-l-yl) ethyl) quinazolin-4(3H)-one

[0096] 4-0X0-3 -(2-oxo-2-(pyrrolidin- 1 -yl)ethyl-3 ^-dihydroquinazoline-ό-carboxylic acid (40 mg, 0.13 mmol) was dissolved in DCM (1OmL) followed by the addition of DIEA ( 0.2 mL), HATU (100 mg) and 3-chlorophenyl piperazine (29 mg, 0.14 mmol) .The mixture stirred at RT over night. The residue was semi- purified by flash chromatography and then further purified by rotary prep TLC using DCM-Ether (1 :1) to gave 6-(4-(3-chlorophenyl) piperazine- l-carbonyl)-3-(2-oxo-2-(pyrrolidin-l-yl) ethyl) quinazolin-4(3H)-one in 40% yield and HPLC purity of > 95%.

Example 11

Synthesis of N-(4-chlorobenzyl)-3-(2-fluorobenzyl)-4-oxo-3,4-dihydroquina zoline-7- carboxamide (Compound 104)

A. Synthesis of methyl 3-(-2-flourobenzyl)-4-oxo-3, 4-dihydoquinazoline-7-carboxylate

[0097] Methyl 4-oxo-3,4-dihydroquinazoline-7-carboxlate 300 mg (1.37 mmol) was dissolved in acetonitrile (20 niL) followed by addition OfK ₂ CO ₃ (100 mg), KI (80 mg) and 2-flourobenzyl chloride (0.2mL, 1.65 mmol). The mixture was refluxed over night. The reaction mixture was concentrated and the residue was purified by flash chromatography (Et ₂ O: DCM, 1:1) to give methyl 3 -(2-flourobenzyl) 4-oxo-3,4-dihydroquinazoline-7- carboxylate in 70% yield.

B. Synthesis of 3-(2-flourobenzyl)-4-oxo-3, 4-dihydroquinazoline-7-carboxylic acid

[0098] Methyl 3-(2-flourobenzyl)-4-oxo-3,4-dihydroquinazoline-7-carboylate 300mg, 0.92 mmol) was dissolved In a mixture OfTHF-MeOH-H ₂ O (1OmL- 3mL-3mL) followed by the addition Of LiOH-H ₂ O (200 mg). The mixture was stirred at RT over night. The solvent evaporated and the residue was dissolved in 4mL of water and then acidified with 2N HCl to pH~3.The solid was filtered off , dried to gave 270 mg 3-(2-flourobenzyl)-4-oxo-3, 4- dihydroquinazoline-7-carboxylic acid in 75 % yield.

C. Synthesis of N-(3-chlorobenzyl)-3-(2-flourobenzyl)-4-oxo-3 ₁ 4-dihvdroquinazoline-7- carboxamide

[0099] 3-(2-flourobenzyl)-4-oxo-3, 4-dihydroquinazoline-7-carboylate (65 mg, 0.218 mmol) was dissolved in DCM (1OmL) followed by the addition of DIEA (0.1 mL), HATU (100 mg) and 4-chlorobenzylamine (34 mg, 0.239mmol) .The mixture was stirred at RT overnight. The residue was semi- purified by flash chromatography and then further purified by rotary prep TLC using DCM-Ether (1 :1) to give the desired product in 65% yield with HPLC purity of >95%.

Example 12

Synthesis of 5-methyl-3 -(2-(2-oxopyrrolidin- 1 -yl)ethyl)-6-(4-phenylpiperazine- 1 - carbonyl)thienor23-d1pyrimidin-4(3H)-one (Compound 92)

A. Synthesis of 2-(2-oxopyiτolidm-l-yl)ethyl methanesulfonate

[00100] To a Stirred solution of l-(2-hydroxyethyl)pyrrolidin-2-one (2.6g, 20 mmol) in pyridine (15ml) was added methanesulfonyl chloride (2.28g, 20 mmol) and the reaction mixture was stirred at RT overnight. Solution was concentrated and diluted with ethyl acetate (50ml) and washed with water (50ml). Ethyl acetate layer was separated, dried over anhydrous sodium sulfate and evaporated to yield 3.0g of 2-(2-oxopyrrolidin-l-yl)ethyl methanesulfonate, as an oil (yield: 75%).

B. Synthesis of methyl 5-methyl-4-oxo-3-(2-(2-oxopyrrolidin-l-yl)ethvl)-3,4-dihvdro thieno [2,3-d]pyrimidine-6-carboxylate

[00101] To a solution of methyl 5-memyl-4-oxo-3,4-dihydromieno[2,3-d]pyrimidine-6- carboxylate (0.8g, 3.5 mmol) in DMF (10 ml) was added NaH (0.28g, 7 mmol) followed by the addition of 2-(2-oxopyrrolidin-l-yl)ethyl methanesulfonate (0.7g, 3.5 mmol). The mixture was then stirred overnight at RT. Reaction was quenched with water (10 ml) and mixture extracted with ethyl acetate. Ethyl acetate layer was separated, dried over anhydrous sodium sulfate and evaporated to yield 0.5g of methyl 5-methyl-4-oxo-3-(2-(2- oxopyrrolidin-l-yl)ethyl)-3,4-dihydrothieno [2,3-d]pyrimidine-6-carboxylate, as an oil (yield: 42.8%).

C. Synthesis of 5-methyl-4-oxo-3-(2-(2-oxopyrrolidin-l-yl)ethyl)-3,4-dihydro thieno [2,3- dlpyrimidine-6-carboxylic acid

[00102] Methyl 5-methyl-4-oxo-3-(2-(2-oxopyiτolidin-l-yl)ethyl)-3,4-dihydr othieno [2,3- d] pyrimidine-6-carboxylate (0.5 g, 1.5 mmol) was dissolved in a mixture of THF-MeOH- H ₂ O (10 mL - 3 mL - 3 mL) followed by the addition Of LiOH-H ₂ O (0.250 g). The mixture was stirred at RT over night. The solvent evaporated and the residue was dissolved in 4mL of water and then acidified with 2N HCl to pH~3.The solid was filtered off , dried to gave 0.290 g of 5-methyl-4-oxo-3-(2-(2-oxopyiτolidin-l-yl)ethyl)-3,4-dihydr othieno [2,3- d]pyrimidine-6-carboxylic acid, in 60 % yield.

D. Synthesis of 5-methyl-3-(2-(2-oxopynOlidin-l-yl)ethyl)-6-(4-phenylpiperaz ine-l- carbonyl)thieno[2,3-d]pyrimidin-4(3H)-one

[00103] To a solution of 5-methyl-4-oxo-3-(2-(2-oxopyrrolidin-l-yl)ethyl)-3,4- dihydrothieno [2,3-d]pyrimidine-6-carboxylic acid, (0.128 g, 0.4 mmol) in DCM (5 mL) was added DIEA (0.37 mL, 1.2 mmol), l-(4-phenyl) piperazine (0.061 ml, 0.4 mmol), and HATU (0.197 g, 0.52 mmol). The reaction mixture was stirred at RT overnight. The reaction mixture was diluted with DCM (20 mL) and the organic layer was washed with sat. NaHCO ₃ aq. (20 mL) and brine (20 mL). The organic layer was separated, dried over Na ₂ SO ₄ , and concentrated to give crude product as a gummy solid. Purification by flash column chromatography using 2% Methanol in DCM as the eluent afforded the 0.093 g of pure 5-methyl-3-(2-(2-oxopyrrolidin- 1 -yl)ethyl)-6-(4-phenylpiperazine- 1 - carbonyl)thieno[2,3-d]pyrimidin-4(3H)-one, (yield:50%).

Example 13

[00104] Following the general procedures set forth in Examples 1-12, the following compounds listed in Table 1 below were prepared. Mass spectrometry was employed with the final compound and at various stages throughout the synthesis as a confirmation of the identity of the product obtained (M+l). For the mass spectrometric analysis, samples were prepared at an approximate concentration of 1 μg/mL in acetonitrile with 0.1% foπnic acid. Samples were then manually infused into an Applied Biosystems API3000 triple quadrupole mass spectrometer and scanned in Ql in the range of 50 to 700 m/z.

Table 1

W

W

Example 14 T-type Channel Blocking Activities of Various Invention Compounds

A. Transformation of HEK cells:

[00105] T-type calcium channel blocking activity was assayed in human embryonic kidney cells, HEK 293, stably transfected with the T-type calcium channel subunits. Briefly, cells were cultured in Dulbecco's modified eagle medium (DMEM) supplemented with 10% fetal bovine serum, 200 U/ml penicillin and 0.2 mg/ml streptomycin at 37 ⁰ C with 5% CO ₂ . At 85% confluency cells were split with 0.25% trypsin/1 mM EDTA and plated at 10% confluency on glass coverslips. At 12 hours the medium was replaced and the cells stably transfected using a standard calcium phosphate protocol and the appropriate calcium channel cDNA's. Fresh DMEM was supplied and the cells transferred to 28°C/5% CO ₂ . Cells were incubated for 1 to 2 days prior to whole cell recording.

[00106] Standard patch-clamp techniques were employed to identify blockers of T-type currents. Briefly, previously described HEK cell lines stably expressing human αic a^ and an T-type channels were used for all the recordings (passage #: 4-20, 37°C, 5% CO ₂ ). Whole cell patch clamp experiments were performed using an Axopatch 200B amplifier (Axon Instruments, Burlingame, Calif.) linked to a personal computer equipped with pCLAMP software. Data were analyzed using Clampfit (Axon Instruments) and SigmaPlot 4.0 (Jandel Scientific). To obtain T-type currents, plastic dishes containing semi-confluent cells were positioned on the stage of a ZEISS AXIOVERT SlOO microscope after replacing

the culture medium with external solution (see below). Whole-cell patches were obtained using pipettes (borosilicate glass with filament, O.D.: 1.5 mm, LD. : 0.86 mm, 10 cm length), fabricated on a SUTTER P-97 puller with resistance values of ~5 Mω (see below for internal solution).

Table 2 External Solution 500 ml - pH 7.4, 265.5 mOsm

Table 3 Internal Solution 50 ml - pH 7.3 with CsOH, 270 mOsm

T-type currents were reliably obtained by using two voltage protocols:

(1) "non-inactivating", and

(2) "inactivation"

[00107] In the non-inactivating protocol, the holding potential is set at -110 mV and with a pre-pulse at -100 mV for 1 second prior to the test pulse at -40 mV for 50 ms. In the inactivation protocol, the pre-pulse is at approximately -85 mV for 1 second, which inactivates about 15% of the T-type channels. test pulse: - 40 mV, 50 ms 0.067 Hz

inactivation pre-pulse: - -85 mV, 1 second

Vholding: -11 ° rnV non-inactivated pre-pulse: -100 mV, 1 second

[00108] Test compounds were dissolved in external solution, 0.1-0.01 % DMSO. After -10 min rest, they were applied by gravity close to the cell using a WPI microfil tubing. The "non-inactivated" pre-pulse was used to examine the resting block of a compound. The "inactivated" protocol was employed to study voltage-dependent block. However, the initial data shown below were mainly obtained using the non-inactivated protocol only. K _< j values are shown for various compounds of the invention in Table 4 measured at 1 μM for the drug of interest except for compound 18 which was measured at 200 nM.

Table 4 T-type Calcium Channel Block