Synthesis of trans-thienyl-3-ethoxycarbonyl-2,3-dihydro[1,5]benzothiazepin-4(5H)-ones

A series of trans-thienyl-3-ethoxycarbonyl-2,3-dihydro[1,5]benzothiazepin-4(5H)-ones 6-8 was synthesized from thienylmethylidenemalonates 3a-3c and 2-aminobenzenethiol 3d in the presence of triethylamine hydrochloride at 160°. The [1,5]benzothiazepines 6-8 were alkylated using 2-dimethylaminochloroethane, 3-dimethylaminochloropropane and 3-(N-piperidino)chloropropane in order to obtain the corresponding 5-aminoalkylbenzothiazepinones 9-14 .