Antitussive effects of azepino[2,1-b]quinazolones

A series of azepino[2,1-b]quinazolones ( C-1 – C-16) have been synthesized and evaluated for their antitussive activity using citric acid-induced cough model in Guinea pigs. The compounds C-1 – C-16 caused notable decrease in cough frequency and increase in cough latency induced by citric acid. C-3 [2,4-dibromo-7,8,9,10-tetrahydroazepino[2,1-b]quinazolin-12(6H)-one] showed notable antitussive effect as compared with codeine (10 mg/kg). Various substitutions were made at Rings A and B, and all substituents like methoxy, hydroxyl, nitro, amino (Ring A) and alkyl, acetyl, benzoyl (Ring B) other than bromine were found to reduce the potential of the unsubstituted 7,8,9,10-tetrahydroazepino[2,1-b]quinazolin-12(6H)-one as antitussive. Graphical Abstract A series of azepino[2,1-b]quinazolones has been synthesized and evaluated for antitussive activity using citric acid-induced guinea pig cough model.