Novel indole-fused, medium-sized ring heterocycles via chloroacetamide photochemistry

Syntheses of derivatives of three novel indole-fused systems based on indol o[2, 1-d][1,5]benzodiazocine, indolo[7, 7a,1-d,e][I, 6]benzodiazonine and p yrrolo[2, 3-b]indolo[5,5a, 6-b,a]quinazoline, the first two including 8- an d 9-membered ring heterocycles, are described. These derivatives resulted f rom the photo-induced cyclization of the respective chloroacetamide precurs ors prepared via N-alkylation of the appropriate indole with 2-nitrobenzyl bromide, subsequent nitro group reduction and then N-chloroacetylation. Str uctural and stereochemical features of these new ring system derivatives ar e discussed.