The present invention relates to new biphenylsulfoximine compounds and, in particular, to their activity as positive allosteric modulators of the dopamine D1 receptor and to their use for the treatment of pathological states for which a stimulator of this receptor activity is indicated. The invention further relates to pharmaceutical compositions containing them and to a process for the preparation of such compounds.
1. A compound of formula (I), a pharmaceutically acceptable salt thereof or any stereoisomer either of the compound of formula (I) or of a pharmaceutically acceptable salt thereof: <img class="EMIRef" id="539410409-ib0049" /> wherein: R<1> is selected from the group consisting of (C<1> -C<4> )-alkyl; R<2> is selected from the group consisting of H and (C<1> -C<4> )-alkyl; R<3> is selected from the group consisting of H, (C<1> -C<4> )-alkyl and halogen; R<4> is selected from the group consisting of CF<3> , CHF<2> , CH<2> F, (C<1> -C<4> )-alkylCF<3> , (C<1> -C<4> )-alkylCHF<2> and (C<1> -C<4> )-alkylCH<2> F; and R<5> is selected from the group consisting of H, halogen, hydroxyl, (C<1> -C<4> )-alkyl, methoxy and O(C<1> -C<4> )-alkyl. 2. The compound according to claim 1, wherein R<1> is selected from -CH<3> , -CH<2> CH<3> , -CH<2> CH<2> CH<3> and -CHCH<3> CH<3> ; R<2> is selected from H, -CH<3> , -CH<2> CH<3> , -CH<2> CH<2> CH<3> and -CHCH<3> CH<3> ; and R<4> is selected from CF<3> , CHF<2> , CH<2> F, -CH<2> CF<3> , -CH<2> CHF<2> , -CH<2> CH<2> F, -CH<2> CH<2> CF<3> , -CH<2> CH<2> CHF<2> and -CH<2> CH<2> CH<2> F. 3. The compound according to any one of claims 1-2, wherein R<3> is selected from H, -CH<3> , -CH<2> CH<3> , F, Cl and Br; and R<5> is selected from H, F, Cl, Br, -OH, -CH<3> and -CH<2> CH<3> . 4. The compound according to any one of claims 1-3, wherein R<1> is selected from -CH<3> , -CH<2> CH<3> , -CH<2> CH<2> CH<3> and -CHCH<3> CH<3> ; R<2> is selected from H, -CH<3> , -CH<2> CH<3> , -CH<2> CH<2> CH<3> and -CHCH<3> CH<3> ; R<3> is selected from H, -CH<3> , -CH<2> CH<3> , F, Cl and Br; R<4> is selected from CF<3> , CHF<2> , CH<2> F, -CH<2> CF<3> , -CH<2> CHF<2> , -CH<2> CH<2> F, -CH<2> CH<2> CF<3> , -CH<2> CH<2> CHF<2> and -CH<2> CH<2> CH<2> F; and R<5> is selected from H, F, Cl, Br, -OH, -CH<3> and -CH<2> CH<3> . 5. The compound according to any one of claims 1-4, wherein R<1> is selected from -CH<3> and -CH<2> CH<3> ; R<2> is selected from H and -CH<3> ; R<3> is selected from H and Cl; R<4> is selected from CF<3> , CHF<2> and CH<2> F; and R<5> is H. 6. The compound according to any one of claims 1-5, selected from 2-(difluoromethoxy)-4'-(S -methylsulfonimidoyl)biphenyl (Ia); 2-(difluoromethoxy)-4'-(N ,S -dimethylsulfonimidoyl)biphenyl (Ib); 2-(difluoromethoxy)-4'-(S -ethylsulfonimidoyl)biphenyl ( Ic ) ; 3'-chloro-2-(difluoromethoxy)-4'-(S -methylsulfonimidoyl)biphenyl (Id); 3'-chloro-2-(difluoromethoxy)-4'-(N ,S -dimethylsulfonimidoyl)biphenyl ( Ie ) ; 3'-chloro-4'-(S -methylsulfonimidoyl)-2-(trifluoromethoxy)biphenyl (If); 3'-chloro-2-(trifluoromethoxy)-4'-(N ,S -dimethylsulfonimidoyl)biphenyl (Ig); 4'-(N ,S -dimethylsulfonimidoyl)-2-(fluoromethoxy)biphenyl (Ih); 2-(fluoromethoxy)-4'-(S -ethylsulfonimidoyl)biphenyl (Ii); 3'-chloro-2-(fluoromethoxy)-4'-(N ,S -dimethylsulfonimidoyl)biphenyl (Ij); 2-(fluoromethoxy)-4'-(S -methylsulfonimidoyl)biphenyl (Ik); (R)-2-(fluoromethoxy)-4'-(S -methylsulfonimidoyl)biphenyl ((R)-Ik); (S )-2-(fluoromethoxy)-4'-(S -methylsulfonimidoyl)biphenyl ((S )-Ik). 7. A compound of formula (I), a pharmaceutically acceptable salt thereof or any stereoisomer either of the compound of formula (I) or of a pharmaceutically acceptable salt thereof, as defined in any one of claims 1-6, for use as a medicament. 8. A compound according to any one of claims 1-6 for use in a method of treating disorders associated with dopamine D1 receptors. 9. A compound according to any one of claims 1-6 for use in the treatment of a disorder selected from schizophrenia, bipolar disorders, autism spectrum disorder, Parkinson's disease, schizophrenia, Alzheimer's disease, senile dementia, HIV-associated dementia, Lewy body dementia, vascular dementia, frontotemporal dementia, Huntington's chorea, Tourette's syndrome, restless leg syndrome (RLS), or tardive dyskinesia, anxiety, depression, major depressive disorder (MDD), treatment-resistant depression (TRD), bipolar disorder, chronic apathy, anhedonia, chronic fatigue, post-traumatic stress disorder, seasonal affective disorder, social anxiety disorder, post-partum depression, serotonin syndrome, attention deficit hyperactivity disorder (ADHD), drowsiness, excessive daytime sleepiness, inattention, impulsivity, compulsive gambling, mild substance abuse, drug dependence and drug abuse relapse; sexual dysfunction, migraine, post-ischemic tubular necrosis, renal failure, hyponatremia, resistant edema, hypertension, congestive heart failure, cardiogenic or septic shock or postoperative ocular hypotonia, obesity, diabetes, hyperglycemia, atherosclerosis and dyslipidemia. 10. The compound according to any one of claims 1-6 for use in the treatment of cognitive impairment and negative symptoms in schizophrenia, bipolar disorders and autism spectrum disorder; mild cognitive impairment associated to Parkinson's disease, schizophrenia, Alzheimer's disease, senile dementia, HIV-associated dementia, Lewy body dementia, vascular dementia, or frontotemporal dementia; motor symptoms in Parkinson's disease. 11. The compound according to any one of claims 1-6 for use in the treatment of cognitive impairment and negative symptoms in schizophrenia and mild cognitive impairment associated to Parkinson's disease. 12. A compound according to any one of claims 1-6 for use in the treatment of Parkinson's disease or schizophrenia. 13. A pharmaceutical composition comprising a therapeutically effective amount of a compound of formula (I), a pharmaceutically acceptable salt thereof or any stereoisomer either of the compound of formula (I) or of a pharmaceutically acceptable salt thereof as defined in any of the claims 1-6, together with one or more pharmaceutically acceptable diluents, excipients or carriers. 14. A process for the preparation of a compound of formula (I), a pharmaceutically acceptable salt thereof or any stereoisomer either of the compound of formula (I) or of a pharmaceutically acceptable salt thereof, as defined in any one of claims 1-6, comprising: a) oxidation of a compound of formula (VI) to obtain the sulfoxide intermediate of formula (VII) <img class="EMIRef" id="539410409-ib0050" /> wherein R<1> , R<3> , R<4> and R<5> are as defined above; and b) imination of intermediate of formula (VII), optionally followed byN- alkylation, to obtain compounds of formula (I). 15. The process according to claim 14, wherein in step a) an asymmetric oxidation of compound of formula (VI) is performed to obtain the corresponding enantiomerically pure sulfoxide intermediate of formula (R)- (VII) or (S)-(VII).