The synthesis of a new series of N‐2 alkylamino derivatives of 4,5‐dihydro‐s‐triazolo[3,4‐d]‐1,5‐benzothiazepine has been accomplished starting from 2,3‐dihydro‐1,5‐benzothiazepin‐4(5H)ones and their 2‐methyl and 2‐aryl derivatives. ‐ All the compounds were tested in vitro for their antimicrobial activity, but none of them showed remarkable activity. ‐ The tricyclic compounds 7a‐j, 8a‐j, 9a‐j, 10a‐j