Patent ID: 6838478

Claim:
A compound of formula I, wherein R 1 represents H; R 2 and R 3 are both hydrogen; R x represents a structural fragment of formula IIa, IIb or IIc, wherein k, l and m independently represent 0, 1, 2, 3 or 4; R 4 and R 5 independently represent H, Si(Me) 3 , 1- or 2-naphthyl, a polycyclic hydrocarbyl group, CHR 41 R 42 or C 1-4 alkyl (which latter group is optionally substituted by one or more fluorine atoms), or C 3-8 cycloalkyl, phenyl, methylenedioxyphenyl, benzodioxanyl, benzofuranyl, dihydrobenzofuranyl, benzothiazolyl, benzoxazolyl, benzimidazolyl, coumaranonyl, coumarinyl or dihydrocoumarinyl (which latter twelve groups are optionally substituted by one or more of C 1-4 alkyl (which latter group is optionally substituted by one or more halo substituent), C 1-4 alkoxy, halo, hydroxy, cyano, nitro, SO 2 NH 2 , C(O)OH or N(H)R 43 ); R 41 and R 42 independently represent cyclohexyl or phenyl; R 6 and R 7 independently represent H, C 1-4 alkyl, C 3-8 cycloalkyl, phenyl (which latter group is are optionally substituted by one or more of C 1-4 alkyl (which latter group is optionally substituted by one or more halo substituent), C 1-4 alkoxy, halo, hydroxy, cyano, nitro, SO 2 NH 2 , C(O)OH or N(H)R 44 ) or together with the carbon atom to which they are attached form a C 3-8 cycloalkyl ring; R 43 and R 44 independently represent H or C(O)R 45 ; and R 45 represents H, C 1-4 alkyl or C 1-4 alkoxy; Y represents (CH 2 ) 2 , CH═CH, (CH 2 ) 3 , CH 2 CH═CH or CH═CHCH 2 , which latter three groups are optionally substituted by C 1-4 alkyl, methylene, oxo or hydroxy; n represents 0, 1, 2, 3 or 4; and B represents a structural fragment of formula IVa or IVc or a pharmaceutically acceptable salt thereof.