When N-[2-(alkylsulfinyl) phenyl]-1H-indole-2-carboxamides with varying degrees of indolic and amidic N-alkylation are heated in an inert solvent or treated with trifluoroacetic anhydride; only compounds in which the amidic nitrogen is methylated cyclize to indolo [3, 2- b]-1, 5-benzothiazepinones (9, 10). Successful cyclization is attributed to the ability of N-Me amides to readily adopt a conformation conducive to cyclization, which other derivatives ...
![5,7-dihydroindolo[3,2-b][1,5]benzothiazepin-6-one Structure](https://image.chemsrc.com/caspic/498/206256-16-8.png)
