Disclosed are compounds of formula (1) and pharmaceutically acceptable salts thereof:

wherein:
R, and R 9 are independently phenyl, phenyl C 1-4 alkyl, phenyl C 2-4 alkenyl or pyridyl, the aromatic moiety optionally substituted by one, two or three of halogen, trifluoromethyl, C 1-4 alkoxy, C 1-4 alkyl, cyano, hydroxy, nitro, NR 10 R 11 or O 2 SNR 10 R 11 wherein R, o and R 11 are independently hydrogen or C 1-6 alkyl or together are C 3-6 polymethylene, or disubstituted at adjacent carbon atoms by C 1-2 alkylenedioxy; C 3-8 cycloalkyl; or aliphatic heterocyclyl having up to six ring atoms the heteroatom(s) being selected from oxygen, sulphur or nitrogen; m and n are independently integers of 0 to 3, such that m + n is 0 to 3; and R z and R 8 are independently hydrogen C 1-4 alkyl or phenyl C 1-4 alkyl, R 3 is C 1-4 alkyl optionally substituted by hydroxy or thiol or phenyl C 1-4 alkyl, or together with R 4 is C 3-6 polymethylene, R 4 is hydrogen, C 1-4 alkyl, phenyl C 1-4 alkyl or as defined with R 3 , or together with R 5 is -(CH 2 ) p -where p is an integer from 2 to 6 such that m + p is 3 to 6, R 6 is hydrogen, C 1-4 alkyl or as defined with R 4 , or together with R 6 is -(CH 2 ) q -where q is an integer from 2 to 6 such that n + q is 3 to 6, R 6 is hydrogen, C 1-4 alkyl, phenyl C 1-4 alkyl or as defined with R 5 , or together with R 7 is C 3-6 polymethylene, and R 7 is C 1-4 alkyl optionally substituted by hydroxy or thiol, phenyl C 1-4 alkyl or as defined with R 6 , in which any phenyl moiety in R 2 ,R 3 ,R 4 ,R 6 ,R 7 and R 8 is optionally substituted by one or two of halogen, trifluoromethyl, C 1-4 alkoxy or C 1-4 alkyl. Such compounds have been found to possess cardiovascular activity, in particular calcium antagonistic activity which indicates that they are of potential use in the treatment of angina.