Amide or thioamide derivatives and their use in the treatment of pain

1. A compound having the formula:

wherein

Z′ is —(CH 2 ) 3 — or cyclohexyl;

Z is selected from a C 1-7 straight or branched chain alkyl, a C 4-8 branched alkylene chain, and a C 2-7 alkenylene chain;

Ar is an aryl group independently selected from an aromatic carbocyclic ring system, a five- or six-membered heteroaromatic ring system and a bicyclic heteroaromatic ring system;

R 3 is selected from a group of substituents (a)-(d) consisting of:

(a) H;

(b) C 1-6 straight chain or C 4-8 branched chain alkyl;

(c) C 3-8 cycloalkyl or C 5-8 cycloalkenyl; and

(d) C 2-6 alkenyl or alkynyl;

wherein the substituents (b)-(d) optionally have at least one substituent independently selected from a group (e)-(i) consisting of:

(e) Ar, —O—Ar or —S—Ar;

(f) OH, O-alkyl or S-alkyl, where alkyl is selected from the substituents (b)-(c);

(g) —NR 4 R 5 , where R 4 and R 5 are independently selected from the substituents (a)-(d) or optionally together form a nitrogen containing ring structure comprising from 2 to 5 carbon atoms;

(h) —NH—C(O)-alkyl, —C(O)-alkyl, —O—C(O)-alkyl or —S—C(O)-alkyl, where alkyl is selected from the substituents (b)-(c); and

(i)F, Cl or Br;

R 6 is selected from a group consisting of Ar and the substituents (a)-(c), where (b) and (c) are optionally substituted with at least one of the substituents (e)-(i);

Ar optionally has at least one substituent independently selected from the substituents (b)-(i); or

a tautomer, solvate or pharmaceutically acceptable salt of said compound.

2. The compound or a tautomer, solvate or pharmaceutically acceptable salt thereof according to claim 1 , wherein Ar is selected from phenyl and naphthyl.

3. The compound or a tautomer, solvate or pharmaceutically acceptable salt thereof according to claim 1 , wherein Z is selected from —CH 2 —, —(CH 2 ) 2 —, —(CH 2 ) 3 —, —(CH 2 ) 4 —, —(CH 2 ) 5 —, —(CH 2 ) 6 —, and —(CH 2 ) .

4. The compound or a tautomer, solvate or pharmaceutically acceptable salt thereof according to claim 1 , wherein R 6 is selected from isopropyl, cyclopentyl, cyclohexyl, phenyl, 4-n-butylphenyl, 4-isopropylphenyl and 2-naphthyl.

5. The compound or a tautomer, solvate or pharmaceutically acceptable salt thereof according to claim 1 , wherein R 2 and R 3 are independently selected from H and 4-chlorobenzyl.

6. The compound or a tautomer, solvate or pharmaceutically acceptable salt thereof according to claim 1 , wherein the compound is selected from a group consisting of:

4-[3-phenyl-1-(6-phenylhexyl)ureido]butyramide;

4-[1-(4-butylbenzyl)-3-phenylureido]butyramide;

4-[1-(4-isopropylbenzyl)-3-phenylureido]butyramide;

4-[1-(4-methylpentyl)-3-phenylureido]butyramide;

N-(4-chlorobenzyl)-4-[1-(3 -cyclohexylpropyl)-3-phenylureido]butyramide;

trans-2-[1-(3-cyclohexylpropyl)-3-phenylurei do]cyclohexanecarboxamide;

4-[1-(3-cyclohexylpropyl)-3-naphthalen-2-yl-ureido]butyramide;

4-[1-(2-naphthalen-2-yl-ethyl)-3-phenylureido]butyramide;

4-[1-(2-cyclohexylethyl)-3-phenylureido]butyramide;

4-(1-phenethyl-3-phenylureido)butyramide;

4-(1-benzyl-3-phenylureido)butyramide;

4-[1-(3-cyclopentylpropyl)-3-phenylureido]butyramide;

4-[3-phenyl-1-(5-phenylpentyl)ureido]butyramide; and

4-[I-(3-cyclohexylpropyl)-3-phenylureido]butyramide.

7. A pharmaceutical composition comprising the compound or a tautomer, solvate or pharmaceutically acceptable salt thereof according to claim 1 and a pharmaceutically acceptable adjuvant, diluent or carrier.

8. The compound according to claim 2 , wherein Ar is phenyl.

9. The compound according to claim 3 , wherein Ar is phenyl

10. The compound according to claim 3 , wherein Z is a C 2-7 straight chain alkyl.

11. The compound according to claim 3 , wherein Z is selected from the group consisting of —(CH 2 )—, —(CH 2 ) 2 —, —(CH 2 ) 3 — and —(CH 2 ) 5 —.

12. The compound according to claim 3 , wherein Z is —(CH 2 )—.

13. The compound according to claim 2 , wherein R 6 is C 3-8 cycloalkyl.

14. The compound according to claim 3 , wherein R 6 is C 3-8 cycloalkyl.

15. The compound according to claim 14 , wherein R 6 is cyclohexyl.

16. The compound according to claim 2 , wherein R 3 is H, C 1-6 straight or C 4-8 branched chain alkyl.

17. The compound according to claim 3 , wherein R 3 is H, C 1-6 straight chain or C 4-8 branched chain alkyl.

18. The compound according to claim 17 , wherein R 3 is H.

19. The compound according to claim 9 , wherein R 6 is C 3-8 cycloalkyl.

20. The compound according to claim 19 , wherein R 6 is cyclohexyl.