Three analogues with restricted flexibility were designed to study the active conformation of verapamil during interaction with the slow calcium channel. Thus cis-and trans-l-(3, 4- dimethoxyphenyl)-4-[N-[2-(3, 4-dimethoxyphenyl) ethyl]-N-methylamino]-rl- cyclohexanecarbonitrile (5a and 5b), and 4-(3, 4-dimethoxyphenyl)-N-[2-(3, 4 dimethoxyphenyl) ethy1]-4-~ yanopiperidine (6), in which the verapamil structure is ...
