Compounds of formula (I) are useful in the treatment of diseases where enhanced M3 receptor activation is implicated, such as respiratory tract diseases: wherein (i) R<1> is C1-C6-alkyl or hydrogen and R<2> is hydrogen or a group -R<7>, -Z-Y-R<7>, -Z-NR<9>R<10> -Z-CO-NR<9>R<10>, -Z-NR<9>-[AE11]C(O)O-R<7>, or -Z-C(O)-R<7> and R<3> is a lone pair, or C1C6-alkyl or (ii) R<1> and R<3> together with the nitrogen to which they are attached form a heterocycloalkyl ring, and R<2> is a lone pair or a group -R<7>, -Z-Y-R<7>, -Z-NR<9>R<10>, -Z-CO-NR<9>R<10>, -Z-NR<9>-[AE12]C(O)O-R<7> or -Z-C(O)-R<7> or (iii) R<1> and R<2> together with the nitrogen to which they are attached form a heterocycloalkyl ring, the ring being substituted by a group -Y-R<7>, -Z-Y-R<7>, -Z-NR<9>R<10> -Z-CO-NR<9>R<10> -Z-NR<9>-[AE13]C(O)O-R<7> or -Z-C(O)-R<7> and R<3> is a lone pair, or C1-C6-aIkyl R<4> and R<5> are independently selected from the group consisting of aryl, arylfused-heterocycloalkyl, heteroaryl, C1-C6-alkyl, cycloalkyl R<6> is -OH, C1-C6-alkyl, C1-C6-alkoxy, hydroxy-C1-C6-alkyl, nitrile, a group CONR<8>2 or hydrogen A is oxygen or sulfur X is alkylidene, alkenylene or alkynylene R<7> is C1-C6-alkyl, aryl, arylfused-cycloalkyl, arylfused-heterocycloalkyl, heteroaryl, aryl(C1-C8-alkyl)-, heteroaryl (C1-C8-alkyl)-, cycloalkyl or heterocycloalkyl R8 is C1-C6-alkyl or hydrogen Z is C1-C16- alkylidene, C2-C16- alkenylene or C2-C16- alkynylene Y is chemical bond or hydrogen R9 and R10 are independently selected from the group consisting of hydrogen, C1-C6-alkyl, aryl, arylfused-heterocycloalkyl, arylfused-cycloalkyl, heteroaryl, aryl(C1-C6-alkyl)-or heteroaryl (C1-C6-alkyl)-group or R9 and R10 together with the nitrogen to which they are attached form a heterocyclic ring having 4-8 ring atoms and any of nitrogen or oxygen.
