Mary E. Eggers, Parag V. Jog, Parag V. Jog
Dec 3, 2007
Citations
0
Influential Citations
11
Citations
Journal
Tetrahedron
Abstract
Abstract When N -[2-(alkylsulfinyl)phenyl]-1 H -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 are unable to achieve. The analogous 3-indoleanilide, N , N- dimethyl N -[2-(ethylsulfinyl)phenyl]-1 H -indole-3-carboxamide ( 17a ), undergoes SES/rearrangement to produce 10 upon heating in p -xylene. An intermediate 3 H -indolinium spirocyclic species is proposed to account for this result.