Muscarinic agonists

1. A compound of the formula (2):

or a salt thereof, wherein

q is 1;

r is 1 or 2;

s is 0 or 1, where the total of r and s is 1 or 2;

R 4 is a hydrogen or a C 1-6 non-aromatic hydrocarbon group which is optionally substituted with one to six fluorine atoms;

R 5 is selected from a C 1-6 non-aromatic hydrocarbon group which is optionally substituted with one to six fluorine atoms and wherein one or two, but not all, carbon atoms of the hydrocarbon group may optionally be replaced by a heteroatom selected from O, N and S and oxidized forms thereof; and a group W or CH 2 W where W is an optionally substituted 5- or 6-membered aromatic ring containing 0, 1, 2 or 3 heteroatoms selected from O, N and S;

R 6 is selected from; COR 7 ; COOR 7 ; CH 2 COR 7 ; CH 2 COOR 7 and a C 1-6 non-aromatic hydrocarbon group which is optionally substituted with one to six fluorine atoms and wherein one or two, but not all, carbon atoms of the hydrocarbon group may optionally be replaced by a heteroatom selected from O, N and S and oxidized forms thereof; wherein R 7 is selected from H and a C 1-6 non-aromatic hydrocarbon group which is optionally substituted with one to six fluorine atoms.

2. The compound according to claim 1 wherein r is 1 and s is 1.

3. The compound according to claim 1 wherein r is 1 or 2 and s is 0.

4. The compound according to claim 1 wherein R 4 is selected from hydrogen and methyl.

5. The compound according to claim 1 wherein R 5 is selected from methyl, ethyl, propyl, isopropyl, cyclopropyl, fluoroethyl, difluoroethyl, butyl and cyclobutyl.

6. The compound according to claim 1 wherein R 5 is a group W or CH 2 W where W is an optionally substituted phenyl, pyridyl or isoxazole ring.

7. The compound according to claim 1 wherein R 6 is selected from methyl, ethyl, trifluoroethyl, hydroxyethyl and methoxyethyl.

8. The compound according claim 1 wherein R 6 is selected from; COR 7 ; COOR 7 ; CH 2 COR 7 ; and CH 2 COOR 7 , wherein R 7 is selected from H, methyl, fluoromethyl, difluoromethyl, trifluoromethyl, ethyl, fluoroethyl, difluoroethyl and trifluoroethyl.

9. The compound according to claim 1 which is

Ethyl 6-{4-[acetyl(cyclopropyl)amino]piperidin-1-yl}-2-azaspiro[3.3]heptane-2-carboxylate;

Ethyl 6-{4-[acetyl(ethyl)amino]piperidin-1-yl}-2-azaspiro[3.3]heptane-2-carboxylate;

Ethyl 2-{4-[acetyl(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(propan-2-yl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(cyclopropyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclopropyl(trifluoroacetyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclopropyl(propanoyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(cyclobutyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[ethyl(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclopropyl(2-methoxyethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclopropyl(2-methoxy-2-oxoethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclopropyl(1,2-oxazol-3-ylmethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Methyl 2-{4-[acetyl(cyclobutyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[ethyl(formyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Methyl 2-{4-[acetyl(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(propyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(2-methylpropyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(cyclopropylmethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-(4-{acetyl[(1-methylcyclobutyl)methyl]amino}piperidin-1-yl)-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(1-methylcyclobutyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-(4-{acetyl[(3-methyloxetan-3-yl)methyl]amino}piperidin-1-yl)-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(2,2-difluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(2-fluoro-2-methylpropyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(2,2-difluoropropyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(3,3-difluorocyclobutyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(2-methoxy-2-methylpropyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-(4-{acetyl[(1-methoxycyclobutyl)methyl]amino}piperidin-1-yl)-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-(4-{acetyl[(1-hydroxycyclobutyl)methyl]amino}piperidin-1-yl)-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(methoxy)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(phenyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(pyridin-2-yl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(benzyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(1,3-oxazol-5-ylmethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[acetyl(1,3-oxazol-2-ylmethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

(1,1- 2 H 2 )-Ethyl 2-{4-[acetyl(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[ethyl(methoxycarbonyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(ethoxycarbonyl)(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(methoxycarbonyl)(propan-2-yl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(methoxycarbonyl)(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[ethyl(2-fluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(2,2-difluoroethyl)(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(methoxycarbonyl)(oxetan-3-yl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclopropyl(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclopropyl(2-hydroxyethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[cyclobutyl(2-hydroxyethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(2-hydroxyethyl)(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(2-methoxyethyl)(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[ethyl(oxetan-3-yl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[oxetan-3-yl(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(2-cyanoethyl)(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-(4-{ethyl[2-(methylsulfonyl)ethyl]amino}piperidin-1-yl)-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[ethyl(methoxy)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(2-hydroxyethyl)(phenyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[benzyl(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[ethyl(1,3-oxazol-5-ylmethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(2-fluoroethyl)(1,3-oxazol-5-ylmethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 2-{4-[(1,3-oxazol-5-ylmethyl)(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate;

Ethyl 6-{4-[acetyl(cyclopropyl)amino]piperidin-1-yl}-2-azaspiro[3.4]octane-2-carboxylate;

Methyl 6-{4-[acetyl(ethyl)amino]piperidin-1-yl}-2-azaspiro[3.4]octane-2-carboxylate or

Ethyl 6-{4-[acetyl(ethyl)amino]piperidin-1-yl}-2-azaspiro[3.4]octane-2-carboxylate,

or a salt of any of the foregoing.

10. The compound according to claim 1 which is ethyl 6-{4-[acetyl(ethyl)amino]piperidin-1-yl}-2-azaspiro[3.3]heptane-2-carboxylate or a pharmaceutically acceptable salt thereof.

11. The compound according to claim 1 which is ethyl 2-{4-[acetyl(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate or a pharmaceutically acceptable salt thereof.

12. The compound according to claim 1 which is ethyl 2-{4-[ethyl(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate or a pharmaceutically acceptable salt thereof.

13. The compound according to claim 1 which is methyl 2-{4-[acetyl(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate or a pharmaceutically acceptable salt thereof.

14. The compound according to claim 1 which is ethyl 2-{4-[acetyl(2,2-difluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate or a pharmaceutically acceptable salt thereof.

15. The compound according to claim 1 which is (1,1- 2 H 2 )-ethyl 2-{4-[acetyl(ethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate or a pharmaceutically acceptable salt thereof.

16. The compound according to claim 1 which is ethyl 2-{4-[(2-methoxyethyl)(2,2,2-trifluoroethyl)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate or a pharmaceutically acceptable salt thereof.

17. The compound according to claim 1 which is ethyl 2-{4-[ethyl(methoxy)amino]piperidin-1-yl}-6-azaspiro[3.4]octane-6-carboxylate or a pharmaceutically acceptable salt thereof.

18. The compound according to claim 1 which is methyl 6-{4-[acetyl(ethyl)amino]piperidin-1-yl}-2-azaspiro[3.4]octane-2-carboxylate or a pharmaceutically acceptable salt thereof.

19. A pharmaceutical composition comprising a compound as defined in claim 1 and a pharmaceutically acceptable excipient.

20. The compound according to claim 1 wherein the compound has a muscarinic M 1 receptor and/or M 4 receptor agonist activity.