DESCRIPTION

The present invention relates to diastereomeric compounds that can be used to improve cognitive functions, in particular learning capabilities and memory performance, more in particular to improve spatial learning capabilities, in human individuals, in particular in aging individuals. More in particular, the present invention refers to new compounds which can be used to treat age-dependent decline of cognitive functions such as spatial memory tasks.

Cognitive decline during aging represents a serious medical and socioeconomic burden in societies with high life expectancy. Aging-induced cognitive impairment is often paralleled by a decrease of dopamine in various brain regions. Dopamine plays a fundamental role in learning and memory involving intrinsic neuronal circuits in the prefrontal cortex and the hippocampus as well as the neuronal network activity between these structures (Werlen et ah, Modulating the map: dopaminergic tuning of hippocampal spatial coding and interactions, Prog. Brain Res. 219:187-216; 2015). The effects of dopamine as a target of treating cognitive disorders, however, depend on the memory systems engaged (Ashby et ah, Differential effects of dopamine-directed treatments on cognition, Neuropsychiatr. Dis. Treat. 11:1859-1875; 2015). Spatial memories that structurally involve the hippocampus and prefrontal-cortex and declarative (Linssen et ah, Methylphenidate produces selective enhancement of declarative memory consolidation in healthy volunteers, Psychopharmacology (Berl), 221:611-619; 2012) and novelty (Takeuchi et ah, The synaptic plasticity and memory hypothesis: encoding, storage and persistence, Philos. Trans. R Soc Lond B Biol Sci. 369:20130288; 2013) memory processes strongly depend on neuromodulatory functions of dopamine. Further, the connectivity between these brain structures (Bertolino et al., Prefrontal-hippocampal coupling during memory processing is modulated by COMT vali58met genotype. Biol. Psychiatry. 60:1250-1258; 2006) as well as synaptic glutamatergic transmission within these structures is strongly influenced by dopamine mainly by the release from the ventral tegmental area. Basal ganglia can be involved in the modulation of non-declarative memories (Foerde and Shohamy, The role of the basal ganglia in learning and memory: insight from Parkinson's disease, Neurobiol. Learn. Mem. 96:624-636; 2011), such as the nucleus accumbens (Mulder et al., Short- and long-term plasticity of the hippocampus to nucleus accumbens and prefrontal cortex pathways in the rat, in vivo, Eur. J. Neurosci 9:1603-1611; 1997; Lopez et al., Opposite effects of shell or core stimulation of the nucleus accumbens on long-term potentiation in dentate gyrus of anesthetized rats, Neuroscience 151:572-8; 2008) and striatum (Sagratella et al., Selective reduction of hippocampal dentate frequency-potentiation in striatally lesioned rats with impaired place learning, Brain Res. 660:66-72; 1994, in conjunction with declarative memory).

The inhibition of the dopamine transporter (DAT) has been targeted to circumvent the problems of task and age dependent functional differences of the dopaminergic system. DAT reuptakes extracellular dopamine into the synapse. Accordingly, the application of dopamine transporter inhibitors (DAT-inhibitors) leads to an increase of extracellular dopamine concentrations (Rowley et al., Differences in the neurochemical and behavioural profiles of lisdexamfetamine methylphenidate and modafinil revealed by simultaneous dual-probe microdialysis and locomotor activity measurements in freely-moving rats, J. Psychopharmacol. 28:254-69; 2014), from which a variety of dopamine receptors can benefit.

Cognitive functions can be influenced and improved by a series of chemical compounds including medication targeting the dopamine transporter (DAT). The dopamine transporter reuptakes extracellular dopamine into the synapse, and inhibitors increase the extracellular concentration of dopamine (Rowley et al., 2014), which then can lead to an improvement of learning and memory. For example, it has been shown that DAT inhibitors affect hippocampal synaptic plasticity in the dentate gyrus (Tsanov et al., The psychostimulant modafinil facilitates water maze performance and augments synaptic potentiation in dentate gyrus, Neuropharmacology 59:9-19; 2010; Jenson et al., Dopamine and norepinephrine receptors participate in methylphenidate enhancement of in vivo hippocampal synaptic plasticity, Neuropharmacology 90:23-32; 2015) and CAi (Swant and Wagner, Dopamine transporter blockade increases LTP in the CAi region of the rat hippocampus via activation of the D3 dopamine receptor, Learn Mem. 13:161-167; 2006) as well as working memory and long-term memory in different learning tasks (including spatial tasks) in rodents (Burgos et ah, Effect of modafmil on learning performance and neocortical long-term potentiation in rats, Brain Res. Bull. 83:238-44; 2010; Li et ah, Balanced dopamine is critical for pattern completion during associative memory recall, PLoS One. 5(10) ei540i. doi: 10.1371/journal. pone.0015401, 2010; Tsanov et ah, The psychostimulant modafmil facilitates water maze performance and augments synaptic potentiation in dentate gyrus. Neuropharmacology. 59:9-19, 2010) and humans (Zilles et ah, Genetic polymorphisms of 5-HTT and DAT but not COMT differentially affect verbal and visuospatial working memory functioning, Eur Arch Psychiatry Clin Neurosci., 2012 Dec; 262(8):667-76). Commonly used inhibitors, however, exert insufficient specificity for DAT and inhibit also noradrenaline and serotonin transporters. This unspecificity can lead to severe side effects on the general arousal level and induces psychiatric like disorders such as depressive attacks (Wood et ah, Psychostimulants and cognition: a continuum of behavioral and cognitive activation, Pharmacol. Rev. 66:193-221; 2014).

Aging related decline in cognitive abilities goes along with degenerated dopaminergic systems in various brain regions including hippocampus and prefrontal cortex. Pre- and post-synaptic dopaminergic components are thereby differently changed across the lifespan thereby impairing cognitive functions such as working and episodic memory and decision making differently (Li and Rieckman, Neuromodulation and aging: implications of aging neuronal gain control on cognition, Curr. Opin. Neurobiol. 29:148-158; 2014) in various age classes. Further, differences in task performance may also be related to mere differences in motivation, rather than cognition.

Hippocampal glutamatergic activity as a critical mechanism of learning and memory formation is regulated by the dendritic spine, actin binding potein drebrin (Merriam et ah, Synaptic regulation of microtubule dynamics in dendritic spines by calcium, F-actin, and drebrin, J. Neurosci., Oct 16533 (42):i647i-82; 2013). Hippocampal dopamine-glutamate interactions are realized by a number of postsynaptic proteins like homer (de Bartolomeis and Tomasetti, Calcium-dependent networks in dopamine-glutamate interaction: the role of postsynaptic scaffolding proteins, Mol. Neurobiol., Oct:46(2):275-96; 2012) and presynaptic regulators of transmitter release like bassoon (Gundelfmger et ah, Role of Bassoon and Piccolo in Assembly and Molecular Organization of the Active Zone. Front Synaptic Neurosci., Jan I2;7:i9. doi: 10.33897fnsyn.2015.00019; 2016). cAMP as a second messenger of dopamine activated adenylate cyclases mediate dopamine downstream signalling involving protein kinase A (PKA) and the cAMP response element-binding protein (CREB) that play pivotal roles in long-term memory formation. Moreover, functional changes of dopamine via hetero-receptor complexes have been reported in the context of cognition and psychiatric diseases (Fuxe et ah, Understanding the role of heteroreceptor complexes in the central nervous system, Curr Protein Pept. Sci. 20i4;i5(7):647; Fuxe et ah, Dopamine heteroreceptor complexes as therapeutic targets in Parkinson's disease, Expert Opin. Ther. Targets. 19:377-98; 2015; Martinez-Pinilla, Dopamine D2 and angiotensin II type 1 receptors form functional heteromers in rat striatum, Biochem. Pharmacol. 96:131-42; 2015).

The term “working memory” can be considered to be a specific form of short-term memory that refers to the ability to retain information within a single trial, i.e. to actively hold multiple pieces of transitory information in the mind where they can be manipulated in a way that makes them useful for goal directed behaviour. According to Alan Baddeley (Working memory, reading and dyslexia. Advances in Psychology 34:141-152, 1986.) working memory can be defined as “a system for the temporary holding and manipulation of information during the performance of a range of cognitive tasks such as comprehension, learning, and reasoning”. The long-term storage of information that remains constant over time and that is gradually acquired over many training sessions is usually assigned to the “reference memory” (D.S. Olton, Mazes, maps, and memory, American Psychologist 34:583, 1979)· That is, in contrast to working memory, reference memory appears to be more comparable to long-term memory because it refers to the ability to store information about a specific fixed situation. According to Fauci et al. (in “Harrison’s Principles of Internal Medicine”, volume 1, pp. 142 to 150, 1988) reference memory refers to information gained from previous experience, either recent or remote, i.e. reference memory refers to knowledge for a certain situation that remains constant over time. As stated by A.N. Guitar in "The Interaction Between Spatial Working and Reference Memory in Rats on a Radial Maze" (Paper 4, 2014; http://ir.lib.uwo.ca/psychd_uht) working memory and reference memory could be defined as independent systems both cognitively and physically. Accordingly, reference memory is or can be compared to long-term memory. The reference memory usually is gradually acquired over many training sessions. Once stored, the reference memory is believed to be relatively stable and resistant to interference. In a spatial task, the reference memory mimics two aspects of episodic memory, namely the “what” (content) and “where” (place) dimensions of an event.

It is recognized that stereoisomers such as enantiomers of a chiral drug may possess pharmacokinetic and pharmacodynamic properties different from their racemates. There is thus a risk for misinterpretation of drug disposition and plasma drug concentration-effect data generated for a racemic drug using a non-stereoselective assay. The data collected for the racemic form of a drug is frequently both quantitatively and qualitatively inaccurate with respect to the individual enantiomers. For example, the clearance of the unresolved drug may indicate concentration- and time-dependence even though this pharmacokinetic process is concentration- and time-independent for each of the enantiomers.

C. J. Loland et ah, Biol. Psychiatry, 2012 September 1, 72 (5), pages 405 to 413 (“R- Modafmil (Armodafmil): A unique dopamine up-take inhibitor and potential medication for psychostimulant abuse”), found out that R-modafmil displays an in vitro profile different from that of cocaine. It was, however, concluded that further trials with R- modafmil as a substitute therapy are warranted.

In WO 03/059873 At pharmaceutical compounds are disclosed comprising both a thiazole group and a quaternary carbon comprising three phenyl groups next to a sulfoxide moiety. These compounds shall furnish a medicament which regulates calcium-activated potassium channels and which acts as modulator of SKca and/or IKca channels. According to this document the proposed pharmaceutical compounds shall be suited for the treatment of diseases or conditions like respiratory diseases such as asthma, cystic fibrosis, chronic obstructive pulmonary disease and rhinorrhea, convulsions, vascular spasms, coronary artery spasms, renal disorders, polycystic kidney disease, bladder spasms, urinary incontinence, bladder outflow obstruction, irritable bowel syndrome, gastrointestinal dysfunction, secretory diarrhoea, ischaemia, cerebral ischaemia, ischaemic hearth disease, angina pectoris, coronary heart disease, traumatic brain injury, psychosis, anxiety, depression, dementia, memory and attention deficits, Alzheimer's disease, dysmenorrhea, narcolepsy, Reynaud’s disease, intermittent claudication, Sjorgren's syndrome, migraine, arrhythmia, hypertension, absence seizures, myotonic muscle dystrophia, xerostomi, diabetes type 11, hyperinsulinemia, premature labour, baldness, cancer, and immune suppression in particular in for reducing or inhibiting undesired immune-regulatory actions, Addison's disease, alopecia areata, Ankylosing spondylitis, haemolytic anemia (anemia haemolytica), pernicious anemia (anemia perniciosa), aphthae, aphthous stomatitis, arthritis, arteriosclerotic disorders, osteoarthritis, rheumatoid arthritis, aspermiogenese, asthma bronchiale, auto-immune asthma, auto-immune hemolysis, Bechet's disease, Boeck's disease, inflammatory bowel disease, Burkitt’s lymphom, Chron's disease, chorioiditis, colitis ulcerosa, Coeliac disease, cryoglobulinemia, dermatitis herpetiformis, dermatomyositis, insulin-dependent type I diabetes, juvenile diabetes, idiopathic diabetes insipidus, insulin-dependent diabetes mellisis, auto- immune demyelinating diseases, Dupuytren's contracture, encephalomyelitis, encephalomyelitis allergic, endophthalmia phacoanaphylactica, enteritis allergic, auto-immune enteropathy syndrome, erythema nodosum leprosum, idiopathic facial paralysis, chronic fatigue syndrome, febris rheumatica, glomerulo nephritis, Goodpasture's syndrome, Graves'disease, Hamman-Rich’s disease, Hashimoto's disease, Hashimoto's thyroiditis, sudden hearing loss, sensoneural hearing loss, hepatitis chronica, Hodgkin's disease, haemoglobinuria paroxysmatica, hypogonadism, ileitis regionalis, iritis, leucopenia, leucemia, lupus erythematosus disseminatus, systemic lupus erythematosus, cutaneous lupus erythematosus, lymphogranuloma malignum, mononucleosis infectiosa, myasthenia gravis, traverse myelitis, primary idiopathic myxedema, nephrosis, ophthalmia symphatica, orchitis granulomatosa, pancreatitis, pemphigus, pemphigus vulgaris, polyarteritis nodosa, polyarthritis chronica primaria, polymyositis, polyradiculitis acuta, psoreasis, purpura, pyoderma gangrenosum, Quervain's thyreoiditis, Reiter's syndrome, sarcoidosis, ataxic sclerosis, progressive systemic sclerosis, scleritis, sclerodermia, multiple sclerosis, sclerosis disseminata, acquired spenic atrophy, infertility due to antispermatozoan antobodies, thrombocytopenia, idiopathic thrombocytopenia purpura, thymoma, acute anterior uveitis, vitiligo, AIDS, HIV, SCID and Epstein Barr virus associated diseases such as Sjorgren's syndrome, virus (AIDS or EBV) associated B cell lymphom, parasitic diseases such as Lesihmania, and immunosuppressed disease states such as viral infections following allograft transplantations, graft vs. Host syndrome, transplant rejection, or AIDS, cancers, chronic active hepatitis diabetes, toxic chock syndrome, food poisoning, and transplant rejection.

US 2002/0183334 is about substituted thioacetamides. The rather broad set of compounds disclosed in US 2002/0183334 shall be suited for the treatment of sleepiness, tiredness, Parkinson's disease, cerebral ischemia, stroke, sleep apneas, eating disorders, attention deficit hyperactivity disorder, cognitive dysfunction, disorders associated with hypofunctionality of the cerebral cortex, depression, schizophrenia, and chronic fatigue syndrome, and also for the promotion of wakefulness, stimulation of appetite, or stimulation of weight gain.

In WO 03/066035 a broad range of thioether sulfonamides is disclosed which shall be suited for the treatment of diabetes mellitus.

US 2005/0234040 refers to tricyclic aromatic and bis-phenyl sulfmyl derivatives. The compounds specified in this document shall furnish medicaments suited for the treatment of excessive sleepiness, promotion and/or improvement of wakefulness, preferably improvement of wakefulness in patients with excessive sleepiness associated with narcolepsy, sleep apnea, preferably obstructive sleep apnea/hypopnea, and shift work disorder), Parkinson's disease, Alzheimer's disease, cerebral ischemia, stroke, eating disorders, attention deficit disorder ("ADD"), attention deficit hyperactivity disorder ("ADHD"), depression, schizophrenia, fatigue, preferably fatigue associated with cancer or neurological diseases, such as multiple sclerosis and chronic fatigue syndrome, stimulation of appetite and weight gain and improvement of cognitive dysfunction.

From EP 2 292 213 At a pharmaceutical composition consisting of a specific polymorphic form of R-(-)-modafinil and one or more pharmaceutically-acceptable carriers, diluents or excipients can be derived by use of which subjects with narcolepsy can be treated ensuring a longer lasting plasma concentration and higher overall exposure at high doses when compared to equivalent amounts of the racemic form of modafinil.

Although numerous attempts have been made it would be desirable to provide a way which would allow to efficiently and effectively cope with known learning and/or memory deficits. Compounds and methods which exhibit a further improvement of memory and learning functions are still sought. It is therefore an object of the present invention to provide agents that increase learning capabilities and memory performance, in particular in aging individuals. It is another object of the present invention to prevent and/or treat age- dependent decline of cognitive functions, and to provide an effective agent which can be used for the treatment of age-dependent decline and/or of disorders that in turn cause an improvement of learning capabilities and memory performance.

Therefore, the present invention provides a chemical compound having the general formula

(I): formula (I) wherein R ₁ is a phenyl group or a substituted phenyl group, wherein substituted means ortho-, meta- or para-substituted with a residue selected from the group consisting of alkyl, cykloalkyl, heterocycloalkyl, hydroxyalkyl, aryl, heteroaryl, alkylthio, ether, hydroxyl, fluoride, chloride, bromide and iodide, and

R ₂ is a meta-substituted phenyl group, wherein substituted means substituted with a residue selected from the group consisting of alkyl, cykloalkyl, heterocycloalkyl, hydroxyalkyl, aryl, heteroaryl, alkylthio, ether, hydroxyl, fluoride, chloride, bromide and iodide; and

R _TA is a substituted or unsubstituted thiophene ring, wherein substituted means substituted with a residue selected from the group consisting of alkyl, cykloalkyl, heterocycloalkyl, hydroxyalkyl, aryl, heteroaryl, alkylthio, ether, hydroxyl, fluoride, chloride, bromide and iodide.

It has been found that those compounds according to formula (I) are preferred in which the substituted or unsubstituted thiophene ring is a 2-thiophene ring, in particular an unsubstituted 2-thiophene ring.

It has been found that, additionally or alternatively, those compounds according to formula (I) are preferred in which the meta-substituent of residue R ₂ is selected from the group consisting of alkyl, cycloalkyl, heterocycloalkyl, alkylamino, in particular dialkylamino, arylamino, in particular diarylamino, hydroxyalkylamino, alkoxy, hydroxyl, carboxylic acid group, carboxylate ester group, halogen, in particular a bromine or chlorine substituent, arylalkyl, hydroxyalkyl, thioalkyl, haloalkyl, haloaryl, haloarylalkyl, haloalkoxy, mono or multi-substituted alkyl, mono or multi-substituted cycloalkyl, mono or multi- substituted heterocycloalkyl, mono or multi-substituted alkylamino, in particular dialkylamino, mono or multi-substituted arylamino, in particular diarylamino, mono or multi-substituted hydroxyalkylamino, mono or multi-substituted alkoxy, mono or multi-substituted arylalkyl, mono or multi- substituted hydroxyalkyl, mono or multi-substituted thioalkyl, mono or multi-substituted haloalkyl, mono or multi-substituted haloaryl, mono or multi-substituted haloarylalkyl, mono or multi-substituted haloalkoxy and carboxylate ester, wherein substituted means substituted with a residue selected from the group consisting of alkyl, cykloalkyl, heterocycloalkyl, hydroxyalkyl, alkylthio, ether, hydroxyl, fluoride, chloride, bromide and iodide. Heterocycloalkyl is preferably selected from the group consisting of morpholino, piperazino and methylpiperazino.

Aryl, i.e.an aryl group in the meaning of the present invention preferably denotes phenyl, and substituted aryl preferably denotes mono or multi- substituted phenyl. Exemplary substituted phenyl include for example -o-C ₆ H ₄ -R’, -m-C ₆ H ₄ -R’ and -p-C ₆ H ₄ -R‘, wherein R’ is an alkyl as defined herein or as defined for residues R ₃ , R ₄ , R ₅ , R ₆ and R ₇ . Fused aryl in the meaning of the present invention preferably denotes an aromatic ring being fused with at least one aromatic ring system, the fused aryl group in particular being made of five to 15 carbon atoms, e.g. naphthyl and anthracenyl. These fused aryl may also be mono or multi- substituted, e.g. l-naphthyl, 2-naphthyl, l-anthracenyl or 2-anthracenyl, as defined herein.

Heteroaryl, i.e. a heteroaiyl group in the meaning of the present invention preferably denotes a 3 to 8-membered heterocyclic aromatic group which contains at least one heteroatom selected from the group consisting of O, N, and S. Heteroaryl in the meaning of the present invention also includes a heteroaiyl ring being fused to another aromatic ring. Both heteroaryl and fused heteroaryl group can also be mono or multi-substituted as defined herein.

Alkyl, i.e. an alkyl group in the meaning of the present invention preferably comprises an alkyl, alkenyl and alkynyl residue, in particular a Ci-C ₆ -alkyl, C ₂ -C ₆ -alkenyl and C ₂ -C ₆ - alkynyl residue. Suitable residues are selected from the group consisting of -CH ₃ , -C ₂ H ₅ , - , - - - , wherein R’ can be defined as residue R ₃ as outlined above for formula (I). R’ as referred to above preferably is hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, tert-butyl, sec-butyl or isobutyl, in particular hydrogen, methyl or i-propyl.

The alkyl group according to one preferred embodiment of formula (I), in particular for residue R ₃ , is methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, and isobutyl, preferably methyl or isopropyl, and more preferably alkyl is selected from the group consisting of methyl, ethyl, iso-propyl, and tert-butyl.

Arylalkyl, i.e. an arylalkyl group in the meaning of the present invention preferably denotes a linear or branched Ci-C ₆ -alkyl substituted with at least one aryl group as defined above, preferably benzyl or phenylethyl. Suitable mono or multi-substituted arylalkyl comprise for example 4-hydroxybenzyl, 3-fluorobenzyl or 2-fluorophenylethyl.

Cycloalkyl, i.e. a cycloalkyl group in the meaning of the present invention preferably denotes a non-aromatic ring system containing three to eight carbon atoms, preferably four to eight carbon atoms. With mono or multi-substituted cycloalkyl one or more of the carbon atoms in the ring may be substituted by a group R’ as defined above, preferably methyl, ethyl, n-propyl, i-propyl, n-, i- or t-butyl. Suitable C ₃ -C ₈ -cycloalkyl groups can be selected from the group consisting of -cyclo-C ₃ H ₅ , -cyclo-C ₄ H ₇ , -cyclo-C ₅ H ₉ , -cyclo-CcH,,, -cyclo- C ₇ H _I3 , and -cyclo-CsH,,.

Heterocycloalkyl, i.e. heterocycloalkyl group in the meaning of the present invention preferably denotes a non-aromatic carbon ring system in which one or more ring carbon atoms have been replaced by a heteroatom functional group such as O, S, SO, S0 ₂ , N, or NR’2, wherein R’ is defined as outlined above. Preferred heterocycloalkyl groups can be selected from the group consisting of morpholine-4-yl, piperazinyl, and l-alkylpiperazine- 4-yk

Hydroxyalkyl, i.e. a hydroxyalkyl group in the meaning of the present invention preferably denotes a hydroxyalkyl group in which the alkyl group is defined as outlined above, preferably methyl, ethyl, n-propyl, i-propyl, n-, i- or t-butyl. Suitable hydroxyalkyl groups are selected from the groups consisting of a hydroxymethyl, hydroxyethyl, hydroxypropyl, and hydroxy-iso-propyl group. The hydroxyalkyl group according to a preferred embodiment of formula (I) is hydroxymethyl. Once bonded the alkyl or methyl group may also be denoted as alkylene or methylene group, respectively.

Alkylthio, i.e. an alkylthio group in the meaning of the present invention preferably denotes an alkylthio group in which the alkyl group is defined as outlined above, preferably for R ₃ , in particular thiomethyl.

Haloalkyl, i.e. a haloalkyl group in the meaning of the present invention preferably denotes a haloalkyl group in which the alkyl group is defined as outlined above, in particular for R ₃ , and wherein said alkyl is substituted by one or more halogen atoms, preferably substituted by one to five halogen atoms, in particular by fluor or chlorine atoms. In a preferred embodiment the haloalkyl group is selected from the group consisting of -C(R ¹⁰ ) ₃ , - preferably F.

Haloaryl, i.e. a haloaryl group in the meaning of the present invention preferably denotes a haloaryl group in which at least one aromatic carbon atom is substituted by one or more halogen atoms, preferably substituted by one to five halogen atoms. Preferably, halogen atoms are selected from the group consisting of fluorine, chlorine and bromine atoms, and preferably fluorine.

Haloarylalkyl, i.e. a haloarylalkyl group in the meaning of the present invention preferably denotes a haloarylalkyl group in which the arylalkyl group is defined as outlined above and wherein at least one aromatic carbon atom of said aryl group is substituted by one or more halogen atoms, preferably substituted by one to five halogen atoms. Preferably, halogen atoms are selected from the group consisting of fluorine, chlorine, bromine and iodine atoms, more preferably from fluorine and chlorine atoms.

Haloalkoxy, i.e. a haloalkoxy group in the meaning of the present invention preferably denotes a haloalkoxy group in which the alkoxy group is defined as outlined above and wherein said alkoxy is substituted by one or more halogen atoms, preferably substituted by one to five halogen atoms, in particular by fluorine, chlorine, bromine and/or iodine atoms, more preferably fluorine and/or chlorine atoms. Preferably, the haloalkoxy group is selected from the group consisting of -OC(R ¹⁰ ) ₃ , -OCR ¹⁰ (R ^10’ ) , -OCR ¹⁰ (R ^10’ )R ^10” , -OC ₂ (R ¹⁰ ) ₅ , -OCH ₂ -C(R ¹⁰ ) ₃ , -OCH ₂ -CR ¹⁰ (R ^10’ ) ₂ , -0CH ₂ -CR ¹⁰ (R ^10’ )R ^10” , -OC ₃ (R ¹⁰ ) ₇ or -OC ₂ H ₄ -C(R ¹⁰ ) _3, wherein R ¹⁰ , R ^10’ , R ^10” represent F, Cl, Br or I, preferably F.

Alkylamino, i.e. an alkylamino group in the meaning of the present invention preferably denotes an alkylamino group in which the alkyl group is defined as outlined above, in particular for R ₃ . The alkylamino group in the meaning of the present invention preferably denotes a (alkyl) ₂ -N-group, i.e. a dialkylamino group, or a alkyl-NH- group. The dialkylamino group is preferred. Alkyl is preferably defined as outlined above.

Arylamino, i.e. a diarylamino group in the meaning of the present invention preferably denotes an arylamino group in which the aryl group is defined as outlined above. The arylamino group denotes a (aryl) ₂ -N-group, i.e. a diarylamino group, or a aryl-NH- group. The diarylamino group is preferred, in particular the diphenylamino group. Aryl is preferably defined as outlined above.

Hydroxyalkylamino, i.e. an hydroxyalkylamino group in the meaning of the present invention preferably denotes an hydroxyalkylamino group in which the alkyl group is defined as outlined above, in particular for R ₃ , and wherein the hydroxyalkylamino group denotes a (HO-alkyl) ₂ -N-group or a HO-alkyl-NH- group, or a (HO-alkyl)-N-(alkyl)- group. Alkyl is preferably defined as outlined above.

Compounds having infinite chains consisting for instance of repeating R ₁ , R ₂ , R ₃ units and the like are not encompassed by this invention.

Constituents which are optionally substituted as stated herein, may be substituted, unless otherwise noted, at any chemically possible position.

Moreover, those diastereomerically enriched or a diastereomerically pure chemical compounds according to formula (I) furnish particularly improved results in terms of learning capabilities, in particular spatial learning capabilities, and/or memory functions, in particular reference memory and/ or working memory, in which RTA is an unsubstituted 2-thiophene ring.

Those compounds according to formula (I) are particularly preferred in which R ₁ is a phenyl group, R ₂ is a meta-substituted phenyl group, wherein substituted means substituted with a residue selected from the group consisting of fluoride, chloride, bromide and iodide, and RTA is an unsubstituted thiophene ring, in particular an unsubstituted 2- thiophene ring.

According to another preferred embodiment in compounds according to formula (I) R ₂ is a meta-substituted phenyl group, wherein substituted means substituted with a residue selected from the group consisting of chloride and bromide, in particular bromide. It is particularly preferred that the aforementioned meta-substituted phenyl group does not contain any other substituent, in other words, the ortho- und para-positions are occupied by hydrogen atoms.

In another preferred embodiment the compound according to formula (I) represents a diastereomeric mixture enriched in one of the four diastereomers of the chemical compound having the general formula (I) or a diastereomerically pure chemical compound of one of the four diastereomers having the general formula (I).

In a further, more preferred embodiment the compound according to formula (I)

Even more preferred, the compound according to formula (I) comprises or is, in particular in an essentially diastereomerically pure form, 2-(((((S),(S)-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- and, essentially free of any 2-(((((S),(R)-3- halophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene. preferred.

In general with the present invention compounds of formula (I) as defined herein are provided for use in therapy, i.e. for use as a medicament, and in particular for treating age- related cognitive decline, more in particular for treating age-related cognitive decline according to 2018 ICD-10-CM Diagnosis Code R41.81 (US), i.e. according to the US version of 2018 ICD-10-CM Diagnosis Code R41.81.

It is of particular interest that with the compounds of formula (I), preferably improvements in cognitive functions, in particular in cognitive flexibility and/or in learning capabilities and/or in memory performance, and/or motivation can be accomplished with human individuals, in particular also with those who do not have memory deficits and/or cognitive defects.

2-(((((R),(R)-3-bromophenyl)(phenyl)methyl)sulfmyl)methyl )thiophene (also referred to as compound 2_2) can also be depicted byway of the following formula:

In general, improving learning capabilities is or comprises improving the spatial learning capabilities and improving memory performance is or comprises improving reference memory and/or working memory tasks, in particular reference memory and working memory tasks, in human individuals.

Accordingly, these results can also be obtained with individuals who do not have defects of cognitive functions, in particular does not have reference memory deficits and/ or working memory deficits, and/or motivation deficits, in particular does not have any reference memory deficits, in particular no such deficits caused by diseases of the brain. The compounds according to the present invention can thus also be administered to and are also effective with healthy individuals to improve cognitive functions, in particular in cognitive flexibility and/or in learning capabilities and/or in memory performance, and/or motivation. Accordingly, the present invention therefore also relates to the use of a compound according to the present invention for the improvement of learning capabilities, in particular spatial learning capabilities, and memory performance, in particular reference memory, in healthy individuals, in particular in healthy aging individuals. However, also young individuals can be a target group for the compounds to the present invention. It could be shown with young rats that the effect of compounds such as scopolamine could be reversed when treated with the compounds according to the present invention, in particular with 2-(((((R),(R)-3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)th iophene (also referred to as compound 2_2).

In addition, the present invention also relates to the use of a compound according to the present invention for the improvement of cognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular spatial learning capabilities, and/or memory performance, more in particular reference memory and/or working memory tasks, and/or of motivation in human individuals with human individuals who have defects of cognitive functions, in particular of cognitive flexibility and/or reference memory deficits and/or working memory deficits, and/or motivation deficits, in particular reference memory deficits, caused by diseases of the brain, and in some cases caused by schizophrenia.

In this regard, a patient can be treated with the compounds according to formula (I), who has defects of cognitive functions, in particular of cognitive flexibility and/or reference memory deficits and/or working memory deficits, and/or motivation deficits, in particular reference memory deficits, caused by Alzheimer; Down syndrome; vascular cognitive impairment; stroke; frontotemporal dementia; behavioural, semantic or progressive aphasia type dementia; dementia with Lewy bodies; subcortical dementias; Parkinson's disease dementia; alcohol related dementia; dementia caused by traumatic brain injury; Huntington's disease related dementia; AIDS-related dementia; attention deficit disorders; reference memory deficiencies related to ageing; reference memory disorders related to viral infections of the brain; endogenous psychotic disorders such as schizophrenia or exogenous psychotic disorders, e.g. caused by drug consumption.

The compound according to formula (I) of the present invention, in particular 2-(((((S),(S)- 3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)3- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, can be used alone or in combination with other cognitive enhancing compounds such as rivastigmin, donepezil, galanthamin, clozapine, risperidone, memantine, olanzapine, aripiprazole, quitiapine, clozapine, Di agonists, nicotinic alfa 7-agonists, d-serine, d- cycloserine. PDE2, 4,9 inhibitors, AMPA agonists, lamotrigine, n-desmethylclozapine, mGlu receptor agonists, GABA A receptor agonists, muscarinic 1 and 4 receptor agonists, to treat lack of cognitive impairments and improve reference memory. improving learning capabilities is or comprises improving the spatial learning capabilities and/or wherein improving memory performance is or comprises improving reference memory and/or working memory tasks, in particular reference memory and working memory tasks,

The compounds according to the present invention are particularly useful for treating patients having learning deficits and/or memory deficits and/or motivation deficits, in particular spatial learning and memory task deficits, due to particular demands in healthy and aging individuals, diseases of the brain, mental disorders or cognitive deficits, especially patients having Alzheimer, Down syndrome, stroke (vascular cognitive impairment), frontotemporal dementia, behavioural, semantic and progressive aphasia type dementia, dementia with Lewy bodies, subcortical dementias, and Parkinson's disease dementia, alcohol related dementia, dementia caused by traumatic brain injury, Huntington's disease related dementia, AIDS-related dementia, attention deficit disorders; or schizophrenia. bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred can be administered to a patient having or being at risk to develop any of the disorders referred to above in an effective amount. It is also possible to administer the compound to healthy individuals for improving learning capabilities and/or memory performance and/or motivation deficits, in particular reference memory, and more preferably spatial learning capabilities and reference memory and/or motivation.

According to a preferred embodiment, it is convenient to administer the compound bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, by a single dosage unit form, especially as a capsule or a tablet. A preferred formulation comprises a soft gelatine capsule containing at least one compound according to formula (I) dissolved in oil within the capsule with one or more emulsifying agents. Accordingly, gelatine capsules are preferred which comprise one or more emulsifying agents and also at least one compound according to formula (I) dissolved in at least one oil.

Preferred dosages comprise administration dosages of about 1 mg/kg to about 25 mg/kg body weight. Suitable dosage forms also comprise formulations comprising at least one compound according to formula (I) in an amount of about 0.1 mg to about 10 g, preferably of about 1 mg to about 1 g, and more preferably of about 10 mg to about 200 mg.

According to a preferred embodiment, the compound of formula (I) according to the bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, can be part of formulations which contain at least or can be administered with one or more compounds, also referred to as co-agents, selected from the group consisting of Rivastigmin, Donepezil, Galanthamin, clozapine, risperidone, memantine, olanzapine, aripiprazole, quitiapine, clozapine, Di agonists, nicotinic alfa 7, agonists, d-serine, d- cycloserine, PDE2,4,9 inhibitors, AMPA agonists, Lamotrigine, n-desmethylclozapine, mGlu receptor agonists, GABA A receptor agonists, and Muscarinic l and 4 agonists or other potential cognitive enhancing compounds.

The object of the present invention has also been solved by the use of a compound bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, in the manufacture of a medicament for the improvement of cognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular spatial learning capabilities, and/or memory performance, more in particular reference memory and/or working memory tasks, and/or motivation in human individuals.

According to another aspect of the present invention the compound according to formula bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, has been found for use in, in particular selectively, inhibiting DAT-mediated dopamine reuptake in the synapses in the brain of a mammal, in particular a human individual, and also in the manufacture of a medicament for inhibiting DAT-mediated dopamine reuptake in the synapses in the brain of a mammal, in particular of a human individual. With the 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, inhibition of DAT (Dopamine transporter) is not only highly effective but also highly specific over SERT (serotonin transporter) and NET (Norepinephrine transporter) inhibition. DAT inhibition with high specificity can be accomplished with the compounds according to formula (I), in particular2-(((((S),(S')-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((S),(S)-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, at an IC50 of not more than 7,5 mM, in particular of not more than 4,5 pM, more in particular of not more than 2,5 pM, even more in particular of not more than 2,0 pM, and more preferably of not more than 1,4 pM.

With 2-(((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilfinyl)methyl )thiophene or 2- (((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thi ophene, more in particular

2-(((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methy l)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2.-(((((R),(R)-

3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, specific DAT inhibition can even be accomplished at concentrations of not more than 1,0 pM, preferably of not more than 0,75 pM and even more preferably of not more than 0,4 pM. Measurements are based on using an in vitro reuptake inhibition assay (as specified in the experimental section).

It has surprisingly been found that 5-((((-S),(S)-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiazole, in particular 5-((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiazole and more in particular 5-((((S),(S)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)-i,3-thiazole is at least 5 times, in particular at least 8 times and more in particular at least 10 times as effective in selectively inhibiting DAT-mediated dopamine reuptake in the synapses in the brain as 5-((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)-i,3-thiazole, 5-((((R),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)-i,3-thiazole, 5-((((S),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)-i,3-thiazole, and (S)-5-

(diphenylmethanesulfinylmethyl)-i,3-thiazole.

Moreover, the object of the present invention has also been solved by a pharmaceutical preparation, also referred to herein by pharmaceutical composition, comprising at least one compound according to formula (I), in particular 2-(((((S),(S ^, )-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, and at least one pharmaceutically acceptable carrier and/or diluent.

Thus, according to another aspect, the present invention relates to a pharmaceutical preparation comprising a compound according to the present invention and a pharmaceutically acceptable carrier or diluent.

Pharmaceutical “carriers”, “diluents” as well as “excipients” are substances to be admixed in a pharmaceutical composition as auxiliary substances to the compound according to the present invention or other compounds with pharmaceutical effect (e.g. that have also neurological or behavioural effects). These auxiliary substances do not have a pharmaceutical effect on their own (they are no “active substance” per se) but may assist to optimise the effectivity of the compound according to the present invention. The substances used as “carriers”, “diluents” and excipients” can often be used interchangeably (i.e. that substances that are used as “diluents” may also serve as “excipients” and/or “carriers”).

In general, “carriers” are substances that improve the delivery and the effectiveness of drugs; “diluents” are substances that dilute the active substance in a pharmaceutical preparation; “excipients” are substances that are admixed to the pharmaceutical formulation for defining its releasing properties.

All such “carriers”, “diluents” and “excipients” (i.e. auxiliary substances, sometimes also the term “excipient” is used as the general term including all such substances) are, as already stated, inactive substances formulated alongside the active ingredient (“API”) of a medication, for the purpose of bulking-up formulations that contain potent active ingredients (thus often also referred to as “bulking agents”, “fillers”, or “diluents”). Bulking up allows convenient and accurate dispensation of a drug substance when producing a dosage form. They also can serve various therapeutic-enhancing purposes, such as facilitating drug absorption or solubility, or other pharmacokinetic considerations. Such substances can also be useful in the manufacturing process, to aid in the handling of the active substance concerned such as by facilitating powder flowability or non-stick properties, in addition to aiding in vitro stability such as prevention of denaturation over the expected shelf life. The selection of appropriate excipients, carriers and diluents also depends upon the route of administration and the dosage form, as well as the active ingredient and other factors. Such substances e.g. serve as antiadherents, binders, coatings, disintegrants, fillers, flavours, colours, lubricants, glidants, sorbents, preservatives, sweeteners, etc.

Drug “carriers” are substances that serve as mechanisms to improve the delivery and the effectiveness of drugs. Drug carriers are usually used in sundry drug delivery systems such as: controlled-release technology to prolong in vivo drug actions; decrease drug metabolism, and reduce drug toxicity.

Carriers are generally also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions.

Drug “diluents” are usually substances that simply dilute or reconstitute a pharmaceutical composition (e.g. after storage in dry form).

The pharmaceutical composition with the at least one compound according to formula (I), in particular 2-(((((S),(S)-3-halophenyl)(phenyl)methyl)siilfinyl)methyl)t hiophene or 2- (((((R),(R)-3-halophenyl)(phenyl)methyl)sulfmyl)methyl)thiop hene, more in particular 2- (((((R),(R)-3-halophenyl)(phenyl)methyl)sulfmyl)methyl)thiop hene, and even more in particular 2-(((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilfinyl)methyl )thiophene or 2- (((((R), (R)-3-chlorophenyl Xphenyl )methyl )sulfinyl) methyl )thiophene, even more in particular 2-(((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)t hiophene, or 2- (((((‘S) ₅ (‘S ^, )-3-bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophe ne or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, even more in particular 2- (((((R),(R)-3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thio phene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, usually comprises said compound in an amount of about o.oi (%w/w) to about 8o (%w/w) in a solid composition or about o.ooi (%w/v) to about 8o (%w/v) in a liquid composition. Preferably the compound according to the present invention is present in an amount of about o.i (%w/w) to about 50 (%w/w) in a solid composition or about 0.01 (%w/v) to about 10 (%w/v) in a liquid composition, especially of about 1 (%w/w) to about o (%w/w) in a solid composition or about 0.1 (%w/v) to about 5 (%w/v) in a liquid composition. As already stated, preferably, the compounds according to formula (I), in particular 2- ((((G¾ _> GS)-3-halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophe ne or 2-(((((R),(R)-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)-3- halophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, and even more in particular 2- (((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilfinyl)methyl)t hiophene or 2-(((((R),(R)-3- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, even more in particular 2- (((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thi ophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, even more in particular 2- (((((R),(R)-3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thio phene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, are provided as a pharmaceutical composition, especially as a pharmaceutical single unit dosage form. Pharmaceutical compositions and single unit dosage forms provided herein comprise a prophylactically or therapeutically effective amount of one or more compounds according to formula (I) and optionally also one or more additional prophylactic or therapeutic agents (e.g., in particular a compound provided herein, or other prophylactic or therapeutic agent), and one or more pharmaceutically acceptable carriers or excipients or diluents. In a specifically preferred embodiment and in this context, the term “pharmaceutically acceptable” means approved by a regulatory agency of the Federal or a state government or listed in the European or U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans.

The term “carrier” refers in one embodiment to a diluent, adjuvant (e.g., Freund's adjuvant (complete and incomplete)), or vehicle with which the therapeutic is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water is a particular carrier when the pharmaceutical composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions.

In one embodiment, pharmaceutical compositions and dosage forms comprise one or more excipients. Suitable excipients are well-known to those skilled in the art of pharmacy, and non-limiting examples of suitable excipients include starch, glucose, lactose, sucrose, gelatine, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. Whether a particular excipient is suitable for incorporation into a pharmaceutical composition or dosage form usually depends on a variety of factors well known in the art including, but not limited to, the way in which the dosage form will be administered to a patient and the specific active ingredients in the dosage form. The composition or single unit dosage form, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents.

Examples of dosage forms include, but are not limited to: tablets; caplets; capsules, such as soft elastic gelatin capsules; cachets; troches; lozenges; dispersions; suppositories; ointments; cataplasms (poultices); pastes; powders; dressings; creams; plasters; solutions; patches; aerosols (e.g., nasal sprays or inhalers); gels; liquid dosage forms suitable for oral or mucosal administration to a patient, including suspensions (e.g., aqueous or non- aqueous liquid suspensions, oil-in-water emulsions, or a water-in-oil liquid emulsions), solutions, and elixirs; liquid dosage forms suitable for parenteral administration to a patient; and sterile solids (e.g., crystalline or amorphous solids) that can be reconstituted to provide liquid dosage forms suitable for parenteral administration to a patient.

Examples of suitable excipients that can be used in oral dosage forms include, but are not limited to, binders, fillers, disintegrants, and lubricants. Binders suitable for use in pharmaceutical compositions and dosage forms include, but are not limited to, corn starch, potato starch, or other starches, gelatine, natural and synthetic gums such as acacia, sodium alginate, alginic acid, other alginates, powdered tragacanth, guar gum, cellulose and its derivatives (e.g., ethyl cellulose, cellulose acetate, carboxymethyl cellulose calcium, sodium carboxymethyl cellulose), polyvinyl pyrrolidone, methyl cellulose, pre-gelatinized starch, hydroxypropyl methyl cellulose, (e.g., Nos. 2208, 2906, 2910), microcrystalline cellulose, and mixtures thereof.

Examples of fillers suitable for use in the pharmaceutical compositions and dosage forms disclosed herein include, but are not limited to, talc, calcium carbonate (e.g., granules or powder), microcrystalline cellulose, powdered cellulose, dextrates, kaolin, mannitol, silicic acid, sorbitol, starch, pre-gelatinized starch, and mixtures thereof. The binder or filler in pharmaceutical compositions provided herein is typically present in from about 50 to about 99 weight percent of the pharmaceutical composition or dosage form.

Suitable forms of microcrystalline cellulose include, but are not limited to, the materials sold as AVICEL-PH-101, AVICEL-PH-103 AVICEL RC-581, AVICEL-PH-105 (available from FMC Corporation, American Viscose Division, Avicel Sales, Marcus Hook, PA), and mixtures thereof. An specific binder is a mixture of microcrystalline cellulose and sodium carboxymethyl cellulose sold as AVICEL RC-581. Suitable anhydrous or low moisture excipients or additives include AVICEL-PH-103™ and Starch 1500 LM.

Disintegrants can be used in the compositions of the present invention to provide solid dosage forms such as tablets that disintegrate when exposed to an aqueous environment. Tablets that contain too much disintegrant may disintegrate in storage, while those that contain too little may not disintegrate at a desired rate or under the desired conditions. Thus, a sufficient amount of disintegrant that is neither too much nor too little to detrimentally alter the release of the active ingredients should be used to form solid oral dosage forms provided herein. The amount of disintegrant used varies based upon the type of formulation, and is readily discernible to those of ordinary skill in the art. Typical pharmaceutical compositions comprise from about 0.5 to about 15 weight percent of disintegrant, specifically from about 1 to about 5 weight percent of disintegrant.

Suitalbe disintegrants that can be used in pharmaceutical compositions and dosage forms include, but are not limited to, agar-agar, alginic acid, calcium carbonate, microcrystalline cellulose, croscarmellose sodium, crospovidone, polacrilin potassium, sodium starch glycolate, potato or tapioca starch, pre-gelatinized starch, other starches, clays, other algins, other celluloses, gums, and mixtures thereof.

Suitable lubricants that can be used in pharmaceutical compositions and dosage forms include, but are not limited to, calcium stearate, magnesium stearate, mineral oil, light mineral oil, glycerin, sorbitol, mannitol, polyethylene glycol, other glycols, stearic acid, sodium lauryl sulfate, talc, hydrogenated vegetable oil (e.g., peanut oil, cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil, and soybean oil), zinc stearate, ethyl oleate, ethyl laureate, agar, and mixtures thereof. Additional lubricants include, for example, a syloid silica gel (AEROSIL 200, manufactured by W.R. Grace Co. of Baltimore, MD), a coagulated aerosol of synthetic silica (marketed by Degussa Co. of Piano, TX), CAB-O-SIL (a pyrogenic silicon dioxide product sold by Cabot Co. of Boston, MA), and mixtures thereof. If used at all, lubricants are typically used in an amount of less than about 1 weight percent of the pharmaceutical compositions or dosage forms into which they are incorporated.

The active ingredients described herein such as the compounds according to formula (I) and/or the co-agents provided herein can be administered by controlled release means or by delivery devices that are well known to those of ordinary skill in the art. Such dosage forms can be used to provide slow or controlled-release of one or more active ingredients using, for example, hydropropylmethyl cellulose, other polymer matrices, gels, permeable membranes, osmotic systems, multilayer coatings, microparticles, liposomes, microspheres, or a combination thereof to provide the desired release profile in varying proportions. Suitable controlled-release formulations known to those of ordinary skill in the art, including those described herein, can be readily selected for use with the active ingredients. Thus provided are single unit dosage forms suitable for oral administration such as, but not limited to, tablets, capsules, gelcaps, and caplets that are adapted for controlled-release.

All controlled-release pharmaceutical products have a common goal of improving drug therapy over that achieved by their non-controlled counterparts. Ideally, the use of an optimally designed controlled-release preparation in medical treatment is characterized by a minimum of drug substance being employed to cure or control the condition in a minimum amount of time. Advantages of controlled-release formulations include extended activity of the drug, reduced dosage frequency, and increased patient compliance. In addition, controlled-release formulations can be used to affect the time of onset of action or other characteristics, such as blood levels of the drug, and can thus affect the occurrence of side (e.g., adverse) effects.

Most controlled-release formulations are designed to initially release an amount of drug (active ingredient) that promptly produces the desired therapeutic effect, and gradually and continually release of other amounts of drug to maintain this level of therapeutic or prophylactic effect over an extended period of time. In order to maintain this constant level of drug in the body, the drug must be released from the dosage form at a rate that will replace the amount of drug being metabolized and excreted from the body. Controlled- release of an active ingredient can be stimulated by various conditions including, but not limited to, pH, temperature, enzymes, water, or other physiological conditions or compounds.

Parenteral dosage forms can be administered to patients by various routes including, but not limited to, oral, subcutaneous, intravenous (including bolus injection), intramuscular, and intra-arterial. Because their administration typically bypasses patients' natural defences against contaminants, parenteral dosage forms are in certain embodiments sterile or capable of being sterilized prior to administration to a patient. Examples of parenteral dosage forms include, but are not limited to, solutions ready for injection, dry products ready to be dissolved or suspended in a pharmaceutically acceptable vehicle for injection, suspensions ready for injection, and emulsions.

Suitable vehicles that can be used to provide parenteral dosage forms are well known to those skilled in the art. Examples include, but are not limited to: Water for Injection USP; aqueous vehicles such as, but not limited to, Sodium Chloride Injection, Ringer's Injection, Dextrose Injection, Dextrose and Sodium Chloride Injection, and Lactated Ringer's Injection; water- miscible vehicles such as, but not limited to, ethyl alcohol, polyethylene glycol, and polypropylene glycol; and non-aqueous vehicles such as, but not limited to, com oil, cottonseed oil, peanut oil, sesame oil, ethyl oleate, isopropyl myristate, and benzyl benzoate.

According to a preferred embodiment, the pharmaceutical preparation of the present invention further comprises one or more compounds selected from the group consisting of Rivastigmin, Donepezil, Galanthamin, clozapine, risperidone, memantine, olanzapine, aripiprazole, quitiapine, clozapine, Di agonists, nicotinic alfa 7, agonists, d-serine, d- cycloserine, PDE2,4,9 inhibitors, AMPA agonists, Lamotrigine, n-desmethylclozapine, mGlu receptor agonists, GABA A receptor agonists, and Muscarinic 1 and 4 agonists or other potential cognitive enhancing compounds, agents.

Preferred dosages of the compound according to formula (I), in particular 2-(((((S),(S ^, )-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(Sj-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, are 0.1 mg to 10 g, preferably of 1 mg to 1 g, especially 10 mg to 200 mg, of the compound according to the present invention. As already stated, the invention relates to the use of a composition according to formula (I) for the manufacture of a medicament. And, the invention also relates to the use of a composition comprising at least one compound according to formula (I) for the manufacture of a remedy i.e. pharmacological treatment or prevention of cognitive impairment, dementia and/or reference memory deficits.

The compound of the formula (I), in particular2-(((((S),(S ^, )-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(<Sj-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, can be administered to humans, rodents other mammals, as therapeutics per se, and as mixtures with one another or in the form of pharmaceutical preparations which allow enteral or parenteral use and which as active constituent contain an effective dose of the compound of formula (I). The effective dose range can easily be adapted to the severity and the need of the individual patient. Preferred doses are from 1 mg to 10 mg/kg body weight, in addition to customary pharmaceutically innocuous excipients and additives.

The proposed therapeutics can be administered orally, e.g. in the form of pills, tablets, coated tablets, sugar coated tablets, hard and soft gelatin capsules, solutions, syrups, emulsions or suspensions. Administration, however, can also be carried out rectally, e.g. in the form of suppositories, or parenterally, e.g. in the form of injections or infusions or percutaneously, e.g. in the form of ointments, creams or tinctures.

In addition to the active compound of formula (I), the pharmaceutical composition can contain further customary, usually inert carrier materials or excipients, in particular as outlined above. Thus, the pharmaceutical preparations can also contain additives, such as, for fillers, extenders, disintegrants, binders, glidants, wetting agents, stabilizers, emulsifiers, preservatives, sweetening agents, colorants, flavorings or aromatizers, buffer substances, and furthermore solvents or solubilizers or agents for achieving a depot effect, as well as salts for changing the osmotic pressure, coating agents or antioxidants.

The compounds of the present invention can be used in the form of one substance alone or in combination with other active compounds - for example with remedies already known to improve reference memory of healthy individuals, in particular of healthy aging individuals.

The invention also provides a pharmaceutical composition comprising compounds of formula (I), in particular2-(((((Sj,(S')-3- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)~3~ chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, or 2-(((((S),(Sj-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, in free form or in the form of pharmaceutically acceptable formulations and together with pharmaceutically acceptable diluents or carriers.

The compounds of formula (I), in particular2-(((((S'),(S')-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, and also the pharmaceutically acceptable salt or solvate thereof can be used as the active principle for improvement of cognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular the spatial learning capabilities, and/or memory performance, more in particular the reference memory and/or the working memory; and/or motivation in human individuals, also in healthy or unimpaired individuals.

The compounds of the present invention according to Formula (I), in particular2- (((((-S') ₅ (‘S ^, )-3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thioph ene or 2-(((((R),(R)-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, are many times more effective and also many times more selective than for example Modafinil (2-(diphenylmethyl) sulfmyl acetamide).

The present invention also relates to the use of the compounds according to Formula (I), in particiilar2-(((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilf inyl)methyl)thiophene or 2- (((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thi ophene, more in particular

2-((((CR),CR)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methy l)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)-

3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, and also to the use of physiologically functional derivatives in the manufacture of a medicament for the improvement of cognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular the spatial learning capabilities, and/or memory performance, more in particular the reference memory and/or the working memory; and/or motivation in human individual, such as individuals of healthy individuals or aging individuals or of individuals with cognitive impairments, or for the treatment of a disease or a therapeutic indication in which improvement of learning capabilities and memory performance, and more in particular of spatial learning and memory tasks is benefrcial.

Preferably, the pharmaceutical composition according to the present invention comprises the compound as defined by Formula (I), in particular2-(((((S ^, ),(S')-3- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)s- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene being particularly preferred, in free form and a pharmaceutically acceptable diluent or carrier for use in the treatment of healthy individual or aging individuals or treatment of a disease or medical condition accompanied by deficits of learning capabilities and memory performance, and more in particular of spatial learning and memory tasks.

However, in general with the present invention also a pharmaceutical composition has been provided comprising the S enantiomer of the compound according to formula (I) and at least one pharmaceutically acceptable carrier and/ or diluent, as defined herein, for use in therapy, i.e. for use as a medicament, in particular for treating age-related cognitive decline, more in particular for treating age-related cognitive decline according to 2018 ICD- 10-CM Diagnosis Code R41.81 (US), i.e. according to the US version of 2018 ICD-10-CM Diagnosis Code R41.81.

The compound according to Formula (I), in particular2-(((((S),(S')-3- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)~3~ chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, can in particular be used for improving cognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular the spatial learning capabilities, and/or memory performance, more in particular the reference memory and/or the working memory; and/ or motivation in human individual, with human individual who do not have defects of cognitive functions and/or reference memory deficits, or any such defects or deficits caused by diseases of the brain. Alternatively, the compound according to Formula (I), in particiilar2-(((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilf inyl)methyl)thiophene or 2-((((CR),CR)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)t hiophene, more in particular

2-((((CR),CR)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methy l)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)-

3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, can be used for human individuals who have defects of cognitive functions and/or reference memory deficits caused by diseases of the brain. The causes for such defects of cognitive functions and/or reference memory deficits are those as mentioned above.

Accordingly, the problem of the present invention is also solved by the use of the compound according to Formula (I), in particular of2-(((((S),(S)-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)~3~ chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, for the preparation of a medicament for improving the cognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular the spatial learning capabilities, and/or memory performance, more in particular the reference memory and/or the working memory; and/or motivation in human individuals, in particular in aging individuals. Preferably, said prepared medicament is used with human individual who do not have defects of cognitive functions and/or reference memory deficits, or any such defects or deficits caused by diseases of the brain. Alternatively, said medicament prepared by use of the e compound according to Formula (I), in particular 2-(((((S),(S)-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, can be used for treating human individuals who have defects of cognitive functions and/or reference memory deficits caused by diseases of the brain. The causes for such defects of cognitive functions and/or reference memory deficits are those as mentioned above.

It has also surprisingly been found that the compound according to Formula (I), in parti cularcognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular the spatial learning capabilities, and/or memory performance, more in particular the reference memory and/or the working memory; and/or motivation in human individual, can be used in improving the cognitive functions, in particular cognitive flexibility and/or learning capabilities, more in particular the spatial learning capabilities, and/or memory performance, more in particular the reference memory and/or the working memory; and/or motivation in human individual, even in case of age-related memory decline. The surprising effects can for example be obtained by use of only 10 mg/kg and even only 1 mg/kg body weight for the compound according to Formula (I), in particular2- ((((Ci>) _s Ci>)-3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl) thiophene or 2-(((((R),(R)-3- chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred. It has also surprisingly been found that the compounds according to Formula (I), in particiilar2-(((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilf inyl)methyl)thiophene or 2- (((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)thi ophene, more in particular

2-((((CR),CR)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methy l)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)~3~ bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2 -(((((R),(R)-

3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, has a very high specificity and potential for DAT inhibition, and did not exhibit any unanticipated off-target activity.

The compounds of formula (I), in particular its (S),(S)-diastereomer, preferably in disastereomerically pure form, surprisingly exhibits a very low risk of or even essentially no risk of side effects. The final concentration of 0,33 pmol/l 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene in the profiler screen was achieved by serial dilution of a DMSO stock solution to the final assay concentration in 2.0% DMSO/Tris buffer. Cellular agonist effect was calculated as a % of control response to a known reference agonist for each target and cellular antagonist effect was calculated as a % inhibition of control reference agonist response for each target. Accordingly, the compounds according to Formula (I), in particular2-(((((S ^, ),(S)-3- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)s- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2.-(((((R),(R)- 3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene or 2-(((((R),(R)s- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, more in particular 2 -(((((R),(R)- 3-bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene being particularly preferred, appear to have an extremely low potential for off-target crossover.

It has also surprisingly been found that the compound according to Formula (I), in particular 2-(((((S),(S)-3-halophenyl)(phenyl)methyl)siilfinyl)methyl)t hiophene or 2- (((((R),(R)-3-halophenyl)(phenyl)methyl)sulfinyl)methyl)thio phene, more in particular 2- (((((R),(R)-3-halophenyl)(phenyl)methyl)sulfinyl)methyl)thio phene, and even more in particular 2-(((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilfinyl)methyl )thiophene or 2- (((((R), (R)-3-chlorophenyl Xphenyl )methyl )sulfinyl) methyl )thiophene, even more in particular 2-(((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl) thiophene, or 2- ((((G¾ _> GS)-3-bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiop hene or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, even more in particular 2- (((((R),(R)-3-bromophenyl)(phenyl)methyl)sulfinyl)methyl)thi ophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene being particularly preferred, can be used in the treatment and/or prevention of alcohol addiction, nicotine addiction or drug addiction, in particular in the treatment and/or prevention of cocaine and/or metamphetamine addiction, and even more in particular in the treatment and/or prevention of cocaine and metamphetamine addiction.

Moreover, the present invention also provides a pharmaceutical preparation comprising the compound according to Formula (I), in particular 2-(((((S),(S)-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)-3- halophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene, more in particular 2-(((((R),(R)-3- halophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, and even more in particular 2- (((((-S') ₅ (‘S ^, )-3-chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thioph ene or 2-(((((R),(R)-3- chlorophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, even more in particular 2-

(((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl) thiophene, or 2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene or 2-(((((R),(R)s- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, even more in particular 2-

(((((R),(R)-3-bromophenyl)(phenyl)methyl)sulfinyl)methyl) thiophene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene being particularly preferred for use in the treatment and/or prevention of alcohol addiction, nicotine addiction or drug addiction, in particular in the treatment and/or prevention of cocaine and/or metamphetamine addiction, and even more in particular in the treatment and/or prevention of cocaine and metamphetamine addiction.

And, it has also surprisingly been found that the compound according to Formula (I), in particular 2-(((((S),(S)-3-halophenyl)(phenyl)methyl)siilfinyl)methyl)t hiophene or 2- (((((R),(R)-3-halophenyl)(phenyl)methyl)sulfmyl)methyl)thiop hene, more in particular 2- (((((R),(R)-3-halophenyl)(phenyl)methyl)sulfmyl)methyl)thiop hene, and even more in particular 2-(((((S),(S)-3-chlorophenyl)(phenyl)methyl)siilfinyl)methyl )thiophene or 2- (((((R), (R)-3-chlorophenyl Xphenyl )methyl )sulfinyl) methyl )thiophene, even more in particular 2-(((((R),(R)-3-chlorophenyl)(phenyl)methyl)sulfmyl)methyl)t hiophene, or 2- (((((S),(S)-3-bromophenyl)(phenyl)methyl)siilfinyl)methyl)th iophene or 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene, even more in particular 2- (((((R),(R)-3-bromophenyl)(phenyl)methyl)sulfmyl)methyl)thio phene, 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfmyl)methyl)thiophene being particularly preferred, are free or essentially free of any side effects such as increased states of arousal, depressive attacks or addiction problems.

“Pharmaceutically acceptable salt” refers to any salt of a compound provided herein which retains its biological properties and which is not toxic or otherwise undesirable for pharmaceutical use. Such salts may be derived from a variety of organic and inorganic counter-ions well known in the art and include: (l) acid addition salts formed with organic or inorganic acids such as hydrochloric, hydrobromic, sulfuric, nitric, phosphoric, sulfamic, acetic, trifluoroacetic, trichloroacetic, propionic, hexanoic, cyclopentylpropionic, glycolic, glutaric, pyruvic, lactic, malonic, succinic, sorbic, ascorbic, malic, maleic, fumaric, tartaric, citric, benzoic, 3-(4-hydroxybenzoyl)benzoic, picric, cinnamic, mandelic, phthalic, lauric, methanesulfonic, ethanesulfonic, 1,2-ethane-disulfonic, 2-hydroxyethanesulfonic, benzenesulfonic, 4-chlorobenzenesulfonic, 2-naphthalenesulfonic, 4-toluenesulfonic, camphoric, camphorsulfonic, 4-methylbicyclo[2.2.2]-oct-2-ene-l-carboxylic, glucoheptonic, 3-phenylpropionic, trimethylacetic, /ert-butylacetic, lauryl sulfuric, gluconic, benzoic, glutamic, hydroxynaphthoic, salicylic, stearic, cyclohexylsulfamic, quinic, muconic acid and the like acids; or (2) salts formed when an acidic proton present in the parent compound either (a) is replaced by a metal ion, e.g., an alkali metal ion, an alkaline earth ion or an aluminum ion, or alkali metal or alkaline earth metal hydroxides, such as sodium, potassium, calcium, magnesium, aluminum, lithium, zinc, and barium hydroxide, ammonia or (b) coordinates with an organic base, such as aliphatic, alicyclic, or aromatic organic amines, such as ammonia, methylamine, dimethylamine, diethylamine, picoline, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, lysine, arginine, ornithine, choline, N,N'-dibenzylethylene-diamine, chloroprocaine, diethanolamine, procaine, N-benzylphenethylamine, N-methylglucamine piperazine, tris(hydroxymethyl)- aminomethane, tetramethylammonium hydroxide, and the like. Specifically preferred salt forms are hexaflorophosphate and chloride salts.

Such salts further include, by way of example only, sodium, potassium, calcium, magnesium, ammonium, tetraalkylammonium and the like, and when the compound contains a basic functionality, salts of non-toxic organic or inorganic acids, such as hydrochloride, hydrobromide, tartrate, mesylate, besylate, acetate, maleate, oxalate and the like. The term "physiologically acceptable cation" refers to a non-toxic, physiologically acceptable cationic counterion of an acidic functional group. Such cations are exemplified by sodium, potassium, calcium, magnesium, ammonium and tetraalkylammonium cations and the like.

The compounds according to the present invention may also be provided as solvates. “Solvate” refers to a compound provided herein or a salt thereof that further includes a stoichiometric or non-stoichiometric amount of solvent bound by non-covalent intermolecular forces. Where the solvent is water, the solvate is a hydrate.

EXAMPLES Experimental procedures

Reaction conditions and yields were not systematically optimized. Anhydrous solvents were purchased from Sigma-Aldrich and were used as such without further purification. All other chemicals and reagents were purchased from VWR International, TCI Europe/Germany, Synthonix, Acros Organics, Activate Scientific, Fluorochem, Enamine and Alfa Aesar. lH and 13C NMR spectra were recorded on a Bruker Avance 500 NMR spectrometer (UltraShield) using a 5-mm switchable probe (PA BBO 500SB BBF-H-D-05- Z, lH, BB = 19F and 31P - 15N) with z axis gradients and automatic tuning and matching accessory (Bruker BioSpin). The resonance frequency for lH NMR was 500.13 MHz and for 13C NMR 125.75 MHz. All measurements were performed for a solution in fully deuterated chloroform or DMSO at 298 K. Standard lD and gradient-enhanced (ge) 2D experiments, like double quantum filtered (DQF) COSY, NOESY, HSQC, and HMBC, were used as supplied by the manufacturer. Chemical shifts are referenced internally to the residual, non-deuterated solvent signal for chloroform lH (d = 7.26 ppm) or DMSO lH (d = 2.50 ppm) and to the carbon signal of the solvent for chloroform 13C (d = 77.00 ppm) or DMSO 13C (d = 39-57 ppm). HRESIMS spectra were obtained on a maXis HD ESI-Qq-TOF mass spectrometer (Bruker Daltonics, Bremen, Germany). Samples were dissolved to 20 pg/mL in MeOH and directly infused into the ESI source at a flow rate of 3 pL/min with a syringe pump. The ESI ion source was operated as follows: capillary voltage: 0.9 to 4.0 kV (individually optimized), nebulizer: 0.4 bar (N2), dry gas flow: 4 L/min (N2), and dry temperature: 200 °C. Mass spectra were recorded in the range of m/z 50 - 1550 in the positive-ion mode. The sum formulas were determined using Bruker Compass DataAnalysis 4.2 based on the mass accuracy (Am/z < 2 ppm) and isotopic pattern matching (SmartFormula algorithm). The purity of the compounds was determined by HPLC either on an UltiMate 3000 series system equipped with VWD detector (Dionex/Thermo Fisher Scientific, Germering, Germany) or on LC-2010A HT Liquid Chromatograph device (Shimadzu Corporation, Tokyo, Japan). Separation was carried out on an Acclaim 120 C18, 2.1 x 150 mm, 3 pm HPLC column (Thermo Fisher Scientific) using LC-MS-grade water and acetonitrile as mobile phase A and B, respectively. The sample components were separated and eluted with a linear gradient from 10% to 90% B in 25 min followed by an isocratic column cleaning and re-equilibration step. The flow rate was 0.2 mL/min and the column oven temperature was set to 25°C. The purity was determined from the UV chromatogram (254 nm) as the ratio of the peak area of the compound to the total peak area (i.e. the sum of the areas of all peaks that were not present in the solvent blank). Based on the HPLC data, all final compounds are ³95% pure. The crude reaction product containing the diastereomeric mixture of 2-(3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene was purified by flash column chromatography on silica gel to yield two enantiomeric mixtures. These mixtures were individually separated by using CHIRALPACK IA semipreparative column (to mm diameter x 20 mm length) (Daicel Inc, Tokyo, Japan) furnishing individual stereoisomers i_i, i_2,

2 _ l, 2 _ 2. For all separations flow rate was set to to mL/min and all of the separations were carried out on the room temperature.

Synthesis of 2-ffff3-bromophenyl)fphenyl)methyl)sulfmyl)methyl)thiophene

Reagents and conditions: (a) BF ₃ .Et ₂ 0, CH ₃ COOH, r.t. overnight; (b) CH ₃ COOH, 30% H O , r.t. overnight.

1.0 g (3.8 mmol) of (3-bromophenyl)(phenyl)methanol and (0.49 g, 3.8 mmol) of thiophen- 2-ylmethanethiol were dissolved in glacial acetic acid. 1.1 equivalents (1.0 mL, 8.7 mmol) of BF ₃ -Et ₂ 0 were added and the reaction mixture was left under stirring overnight at room temperature. The reaction mixture was then poured over ice, a small amount of water was added and the acetic acid was neutralized with addition of solid NaHC0 ₃ . The product was then extracted (3x) with 50 mL of EtOAc. Organic layers were collected, combined, dried over anhydrous Na ₂ S0 ₄ , filtered and concentrated under reduced pressure affording 1.13 g of 2-((((3-bromophenyl)(phenyl)methyl)thio)methyl)thiophene as yellow oily product (yield 79.21 %). 30% H ₂ 0 ₂ (0.30 mL) was added to the solution of 2-((((3- bromophenyl)(phenyl)methyl)thio)methyl)thiophene (1.13 g 3.01 mmol) in glacial acetic acid (12 mL). The reaction mixture was stirred at room temperature during 24 h. Then, the reaction mixture was neutralized with cold 5% sodium bicarbonate solution. The reaction product was extracted (3 x 50 mL) with EtOAc and dried over anhydrous Na ₂ S0 _4. The organic solution was concentrated under reduced pressure and the residue purified by flash column chromatography on silica gel (2.5% MeOH in DCM). The product was dried in high vacuum to give 0.71 g of the racemic/diastereomeric mixture as a pale yellow solid (yield 60.3%). The racemic/diastereomeric mixture was further separated into two individual pairs of enantiomers by means of MPLC system equipped with glass column filled packed with silica gel. Toluol/EtOAc = 80/20 was used the mobile phase and the separation was carried out with the flow rate of 5 ml. Individual pairs of enantiomers were further separated into individual enantiomers (i_i, i_2, and 2_i, 2_2) by means of semipreparative chiral HPLC method. Semipreparative HPLC was equipped with CHIRALPAK IA column (10 mm F x 25 cm L) (Daicel Inc, Tokyo, Japan) and ethyl-acetate was used as the mobile phase.

1-1: HRESIMS m/z 390.9811 [M+H] ⁺ (calcd for C ₁₈ H ₁₆ BrOS ₂ ⁺ , 390.9820, D = 2.3 ppm). Ret. time 28.23 min, purity 98.42%. Ret. time 6.75 min, enantiomeric purity >99%. Ή NMR (500 MHz, CDCl ₃ -d, 23°C): d = 7.54 (CH-2, aromatic), 7.46 (CH-4, aromatic), 7.44 (CH-3,5, phenyl), 7.39 (CH-6, aromatic), 7.39 (CH-2, 6, aromatic), 7.39 (CH-4, phenyl), 7.34 (CH, thiophene-5), 7.24 (CH-5, aromatic), 7.06 (CH, thiophene-4), 6.95 (CH, thiophene-3),

4.69 (s, lH, CH), 4-10/3-89 (AB, 2H, CHa). ¹³ C NMR (125.75 MHz, CDCl ₃ -d, 23°C): d = 136.60 (C-i, aromatic), 134.79 (C-i, phenyl), 132.40 (C-2, aromatic), 131.50 (C-4, aromatic), 130.12 (C-5, aromatic), 129.78 (C-2, thiophene), 129.48 (CH-3,5, phenyl), 129.18 (C-3, thiophene), 128.74 (CH-2, 6, phenyl), 128.74 (C-4, phenyl), 128.33 (C-6, aromatic), 126.98 (C-5, thiophene), 127.33 (C-4, thiophene), 122.70 (C-3, aromatic), 68.67 (CH), 50.09 (CH ₂ ).

1-2: HRESIMS m/z 390.9810 [M+H] ⁺ (calcd for C ₁₈ H ₁₆ BrOS ₂ ⁺ , 390.9820, D = 2.7 ppm). Ret. time 26.50 min, purity 96.86%. Ret. time 9.10 min, enantiomeric purity >99%. Ή NMR (500 MHz, CDCl ₃ -d, 23°C): d = 7.54 (CH-2, aromatic), 7.46 (CH-4, aromatic), 7.44 (CH-3,5, phenyl), 7.39 (CH-6, aromatic), 7.39 (CH-2, 6, aromatic), 7.39 (CH-4, phenyl), 7.34 (CH, thiophene-5), 7.24 (CH-5, aromatic), 7.06 (CH, thiophene-4), 6.95 (CH, thiophene-3),

4.69 (s, lH, CH), 4-10/3-89 (AB, 2H, CH;,). ¹³ C NMR (125.75 MHz, CDCl ₃ -d, 23°C): d = 136.60 (C-i, aromatic), 134.79 (C-1 _, phenyl), 132.40 (C-2, aromatic), 131.50 (C-4, aromatic), 130.12 (C-5, aromatic), 129.78 (C-2, thiophene), 129.48 (CH-3,5, phenyl), 129.18 (C-3, thiophene), 128.74 (CH-2, 6, phenyl), 128.74 (C-4, phenyl), 128.33 (C-6, aromatic), 126.98 (C-5, thiophene), 127.33 (C-4, thiophene), 122.70 (C-3, aromatic), 68.67 (CH), 50.09 (CH ₂ ).

2_i: HRESIMS m/z 390.9812 [M+H] ⁺ (calcd for C ₁₈ H ₁₆ BrOS ₂ ⁺ , 390.9820, D = 2.2 ppm). Ret. time 26.36 min, purity 96.83%. Ret. time 7.15 min, enantiomeric purity 99.21%. Ή NMR (500 MHz, CDCl ₃ -d, 23°C): d = 7.55 (CH-2, aromatic), 7.49 (CH-4, aromatic), 7.42 (CH-2,6, aromatic), 7.41 (CH-3,5, phenyl), 7.39 (CH-6, aromatic), 7.38 (CH-4, phenyl), 7.34 (CH, thiophene-5), 7.28 (CH-5, aromatic), 7.06 (CH, thiophene-4), 6.97 (CH, thiophene-3),

4.69 (s, lH, CH), 4-10/3-90 (AB, 2H, CH ₂ ). ¹³ C NMR (125.75 MHz, CDCl ₃ -d, 23°C): d = 138.04 (C-i, aromatic), 133.22 (C-1, phenyl), 131.79 (C-2, aromatic), 131.50 (C-4, aromatic),

130.69 (C-5, aromatic), 130.04 (C-2, thiophene), 129.71 (CH-2,6, phenyl), 129.02 (C-3, thiophene), 128.83 (CH-3,5, phenyl), 128.69 (C-4, phenyl), 127.43 (C-4, thiophene), 127.35 (C-6, aromatic), 126.90 (C-5, thiophene), 123.21 (C-3, aromatic), 68.03 (CH), 50.33 (CH ₂ ).

2_2: HRESIMS m/z 390.9810 [M+H] ⁺ (calcd for C ₁₈ H ₁₆ BrOS ₂ ⁺ , 390.9820, D = -2.6 ppm). Ret. time 26.36 min, purity 96.40%. Ret. time 10.28 min, enantiomeric purity 99.61%. Ή NMR (500 MHz, CDCl ₃ -d, 23°C): d = 7.55 (CH-2, aromatic), 7.49 (CH-4, aromatic), 7.42 (CH-2,6, aromatic), 7.41 (CH-3,5, phenyl), 7.39 (CH-6, aromatic), 7.38 (CH-4, phenyl), 7.34 (CH, thiophene-5), 7.28 (CH-5, aromatic), 7.06 (CH, thiophene-4), 6.97 (CH, thiophene-3),

4.69 (s, lH, CH), 4-10/3-90 (AB, 2H, CH ₂ ). ¹³ C NMR (125.75 MHz, CDCl ₃ -d, 23°C): d = 138.04 (C-i, aromatic), 133.22 (C-i, phenyl), 131.79 (C-2, aromatic), 131.50 (C-4, aromatic),

130.69 (C-5, aromatic), 130.04 (C-2, thiophene), 129.71 (CH-2,6, phenyl), 129.02 (C-3, thiophene), 128.83 (CH-3,5, phenyl), 128.69 (C-4, phenyl), 127.43 (C-4, thiophene), 127.35 (C-6, aromatic), 126.90 (C-5, thiophene), 123.21 (C-3, aromatic), 68.03 (CH), 50.33 (CH ₂ ).

Attribution of absolute configuration (AC)

Attribution of absolute configuration (AC) of compounds i_i, i_2, 2_i, 2_2 was performed using vibrational-circular dichroism (VCD) method. Absolute configuration of diastereomer i_i was assigned as Si (S) Cl (R), i.e. i_i = 2-(((((S),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene ; that of

1 _ 2 was assigned Si (R) Cl (S), i.e. i_2 =2-(((((R),(S)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene ; that of

2 _ 1 was assigned Si (S) Cl (S), i.e. 2_i =2-(((((S),(S)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene ; and that of

2 _ 2 was assigned Si (R) Cl (R), i.e. 2_2 =2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene.

Monoamine transporter reuptake inhibition

Uptake inhibition measurements were performed as described in S. Sucic et al. (The N Terminus of Monoamine Transporters Is a Lever Required for the Action of Amphetamines. J. Biol. Chem. 2010, 285 (14), 10924-10938) and Kalaba et al. (Heterocyclic Analogues of Modafinil as Novel, Atypical Dopamine Transporter Inhibitors. J. Med. Chem. 2017, 60 (22), 9330-9348). Dulbecco’s modified Eagle’s medium (DMEM), trypsin and fetal calf serum (FCS) were purchased from Sigma-Aldrich Handels GmbH (Austria). [3H]5-HT (Hydroxytryptamine creatinine sulfate; 5-[I,2-3H[N]]; 45.3 Ci/mmol), [3H]DA (Dihydroxyphenylethylamine; 3,4-[ring-2,5,6-3[H]]-Dopamine; 55.8 Ci/mmol) and

[3H]MPP+ (Methyl-4-phenylpyridinium iodide; i-[methyl-3H]; 80 Ci/mmol) were purchased from Perkin Elmer, Boston, MA. Inhibition of the DAT, NET, and SERT was assessed in human embryonic kidney 293 (HEK 293) that stably express the human DAT, NET, and SERT. Cells were grown as monolayers in 96-well plates pre-coated with poly-D- lysine (PDL) (4x104 cells/well) 24 h prior to the experiment. On the day of the experiment, the medium was aspirated, and each well was washed with warm (30 °C) 0.1 mL of Krebs- HEPES buffer (KHB; 10 mM HEPES, 120 mM NaCl, 3 mM KC1, 2 mM CaCl ₂ -2H ₂ 0, 2 mM MgCl ₂ -6H ₂ 0, 5 mM D-(+)-Glucose monohydrate, pH 7.3). The cells were pre-incubated for 5 min in KHB containing 1% of dimethyl sulfoxide and increasing concentrations of the test compound. After aspiration of the preincubation solution, the cells were incubated in KHB containing increasing concentrations of the compound with the addition of 0.2 mM [3H]- dopamine (for DAT), 0.02 pM [3H]-MPP+ (for NET) and 0.2 pM [3H]-5-HT (for SERT). Incubation times were 1 min for DAT and SERT and 3 min for NET. Non-specific [3H]- dopamine and [3H]-MPP+ uptake in the presence of 30 pM cocaine was subtracted from total uptake. Non-specific [3H]-5-HT uptake in the presence of 30 pM paroxetine was subtracted from total uptake. After incubation at room temperature, reactions were stopped by the addition of 0.1 mL of ice-cold KHB. Finally, cells were lysed with 0.3 mL of 1% SDS and released radioactivity was measured by a liquid scintillation counter (Tri-carb-2300TR, Perkin Elmer). Non-linear regression analysis (GraphPad Prism version 5.0, GraphPad Software, San Diego, CA, USA) was used for calculation of IC ₅₀ values.

Table ¹⁾

1) Values are means of at least three inc ependent experiments. As could be shown, the compounds of the present invention effectively and selectively inhibit the dopamine transporter (DAT) thereby inhibiting reuptake of extracellular dopamine into the synapse and increasing the extracellular concentration of dopamine, which then leads to improved learning capabilities, in particular spatial learning capabilities, and/or to an improved reference memory. Different from commonly used inhibitors, DAT inhibition is rather specific, and noradrenaline and serotonin transporters are not or at least not remarkably inhibited with the compounds of the present invention. Specificity is highest with 2-(((((R),(R)-3- bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiophene. Consequently, with the use of the compounds of the present invention unwanted side effects may be omitted.

This was confirmed by comparative binding tests with cocaine. While with cocaine the IC ₅₀ (mM, mean ± SE) was determined to be 0.52 ± 0.12 (value is means of five independent experiments), with compound 2_2 the IC ₅₀ (mM, mean ± SE) was determined to be 0.17 ± 0.02 (value is means of three independent experiments). Accordingly, the binding affinity of compound 2_2 is significantly stronger than that of cocain. And, it was also found that compound 2_2, different from compounds such as Amphetamines, does not induce release of dopamin from presynaptic cells. Compound 2_2 should therefore not cause any addiction problems itself.

Although modifications and changes maybe suggested by those skilled in the art, it is the intention of the applicant to embody within the patent warranted hereon all changes and modifications as reasonably and probably come within the scope of this contribution to the art. The features of the present invention which are believed to be novel are set forth in detail in the appended claims. The features disclosed in the description as well as the claims could be essential alone or in every combination for the realization of the invention in its different embodiments.