Potential antidiarrheal agents: 1-(11-Cyano-6,11-dihydrodibenzo[b,e]thiepin-11-yl-alkyl)- and 1-(10-cyano-10,11-dihydrodibenzo[b,f]thiepin-10-yl-alkyl)-4-substituted piperidines
Substitution reactions of 11-(2-bromoethyl)- and 11-(3-bromopropyl)-6,11-dihydrodibenzo[b,e]thiepin-11-carbonitrile and further of 10-(2-bromoethyl)- and 10-(3-bromopropyl)-10,11-dihydrodibenzo[b,f]thiepin-10-carbonitrile with ethyl 4-phenylpiperidine-4-carboxylate, 4-phenylpiperidin-4-ol, 4-(2-tolyl)piperidin-4-ol, 4-(4-fluorophenyl)piperidin-4-ol, 4-(2-oxobenzimidazolin-1-yl)-piperidine and 1-phenyl-1,3,8-triazaspiro[4,5]decan-4-one afforded the tricyclic piperidinoalkyl nitriles IV-XIII which are cyclic analogues of the antidiarrheal agents diphenoxylate (I) and loperamide (III). Out of the compounds prepared only IV and XI showed a significant inhibitory effect towards diarrhea elicited by intravenously administered serotonin in mice.