Biphenyl compounds useful as muscarinic receptor antagonists

A compound of formula Ia:

• wherein:
• a is 0 or an integer of from 1 to 5;
• each R1 is independently selected from (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl, (3-6C)cycloalkyl, cyano, halo, —OR1a, —C(O)OR1b, —SR1c, —S(O)R1d, —S(O)2R1e, —NR1fR1g, —NR1hS(O)2R1i, and —NR1jC(O)R1k;
• where each of R1a, R1b, R1c, R1d, R1e, R1f, R1g, R1h, R1i, R1j, and R1k is independently hydrogen, (1-4C)alkyl or phenyl(1-4C)alkyl;
• b is 0 or an integer of from 1 to 4;
• each R2 is independently selected from (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl, (3-6C)cycloalkyl, cyano, halo, —OR2a, —C(O) OR2b, —SR2c, —S(O)R2d, —S(O)2R2e, —NR2fR2g, —NR2hS(O)2R2i, and —NR2jC(O)R2k;
• where each of R2a, R2b, R2c, R2d, R2e, R2f, R2g, R2h, R2i, R2j, and R2k is independently hydrogen, (1-4C)alkyl or phenyl(1-4C)alkyl;
• W represents O or NWa, where Wa is hydrogen or (1-4C)alkyl;
• c is 0 or an integer from 1 to 5;
• each R3 independently represents (1-4C)alkyl or two R3 groups are joined to form (1-3C)alkylene, (2-3C)alkenylene or oxiran-2,3-diyl;
• m is 0 or 1;
• R4 is selected from hydrogen, (1-4C)alkyl, and (3-4C)cycloalkyl;
• n is 0 or 1;
• Ar1 represents pyridine or furan;
• q is 0 or 1;
• R6 is selected from hydrogen, (1-4C)alkyl, and (3-4C)cycloalkyl;
• r is 0, 1 or 2;
• R7 is selected from hydrogen, (1-4C)alkyl, (3-4C)cycloalkyl, —C(O)(1-4C)alkyl, -(1-4C)alkyleneC(O)OR7a, —C(O)heterocyclyl, —C(O)CH(NH2)(1-4C)alkyleneQ, -(1-4C)alkyleneC(O)Q′, —C(O)(1-4C)alkyleneQ′, and —S(O)2(1-4C)alkyleneQ′;
• where Q is a nitrogen-containing substituent selected from —NR7bR7c and heteroaryl;
• Q′ is a nitrogen-containing substituent selected from —NR7dR7e and heterocyclyl;
• R7a is hydrogen or (1-4C)alkyl;
• each of R7b, R7c, R7d and R7e independently represents hydrogen, (1-4C)alkyl, (3-6C)cycloalkyl or hydroxyphenyl, and where (1-4C)alkyl is unsubstituted or substituted by 1 or 2 substituents independently selected from amido, cyano, furyl, hydroxyl, and methylimidazolyl;
• the heterocyclyl contains 1 or 2 nitrogen atoms, and is unsubstituted or substituted by 1 or 2 substituents independently selected from hydroxyl, amido, (1-4C)alkoxy, oxo, —S(O)2(1-4C)alkyl, —(CH2)O(1-4C)alkyl, -(1-4C)alkyleneOH, —NR7fR7g and —C(O)NR7hR7i, where each of R7f, R7g R7h and R7i independently represents hydrogen or (1-4C)alkyl;
• and the heteroaryl contains 1 or 2 nitrogen atoms;
• X1 is selected from (1-3C)alkylene, —C(O)(1-3C)alkylene, (1-3C)alkyleneC(O)—, —SO2—, —SO2(1-3C)alkylene and (1-3C)alkyleneSO2—;
• where the alkylene group in any X1 is optionally substituted with 1 or 2 substituents independently selected from (1-4C)alkyl and —NRXaRXb;
• wherein RXa and RXb are independently selected from hydrogen and (1-4C)alkyl;
• s is 0, 1 or 2;
• each R8 independently represents (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl, (3-6C)cycloalkyl, cyano, nitro, halo, N,N-di(1-4C)alkylamino(2-4C)alkoxy, —OR8a, —C(O)OR8b, —SR8c, —S(O)R8d, —S(O)2R8e or —NR8fR8g;
• each of R8a, R8b;
• R8c;
• R8d, R8e, R8f and R8g is independently hydrogen, (1-4C)alkyl, (3-6C)cycloalkyl, phenyl or phenyl(1-4C)alkyl, wherein each phenyl group is unsubstituted or substituted by 1 or 2 substituents independently selected from halo, (1-4C)alkyl and (1-4C)alkoxy;
• R9 is selected from hydrogen, (1-4C)alkyl, (1-4C)alkyleneNR9aR9b, and phenyl, each of R9a and R9b is independently hydrogen or (1-4C)alkyl;
• or R9 is taken together with R8 to form a ring having 1 to 2 oxygen atoms, where said ring is unsubstituted or substituted by 1 or 2 (1-4C)alkyl substituents;
• and
• wherein each alkyl and alkoxy group in R1, R1a-1k, R2, R2a-2k, R3, R8, R8a-8g, R9, and R9a-9b is optionally substituted with 1 to 5 fluoro substituents;
• or a pharmaceutically acceptable salt or solvate or stereoisomer thereof.