G. Bobowski
Oct 1, 1981
Citations
0
Influential Citations
14
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
The condensation of 1H-indol-3-ethanamine derivatives 1 with 1,2-cyclohexanedione (2) and subsequent transformation of the resulting 2-[[2-(1H-indol-3-yl)ethyl]imino]cyclohexanones (3) into 2′,3′,4′,9′-tetrahydrospiro[cyclohexane-1,1′-(1H)pyrido[3,4-b]indol]-2-ones 4 using Pictet-Spengler reaction conditions is described. The reaction of 4 with acrylonitrile gave a mixture of pentacyclic derivatives, 2,3,4,4a,5,6,9,14-octahydro-4a-hydroxy-1H,8H-pyrido[3,4-b:2,1-i']diindole-5-carbonitriles 12. Treatment of 4 with alkyl and aryl isocyanates (14) at room temperature gave 5-substituted-2,3,4,4a,9,14-hexahydro-4a-hydroxy-1H,8H-indolo[2′,3′:3,4]pyrido[1,2-c]benzimidazol-6-(5H)ones 16. Dehydration of 16 gave 5-substituted-2,3,9,14-tetra-hydro-1H,8H-indolo[2′,3′-3,4]pyrido[1,2-c]benzimidazol-6-(5H)ones (17). Spectral and chemical evidence is presented to confirm structures 4, 12, 16, and 17.