| Abstract: | Oxidative heterocyclization of methyl 3-{1-2-(carbamoylhydrazinylidene)]ethyl}-2-methyl-5-(methoxycarbonyl)amino]-1H-indole-1-carboxylate by the action of selenium dioxide in acetic acid and heating of the corresponding thiosemicarbazone in boiling acetic anhydride gave 1,2,3-selenadiazole and 2,3-dihydro-1,3,4-thiadiazole derivatives, respectively. Methyl 3-acetyl-2-methyl-5-(methoxycarbonyl)amino]-1H-indole-1-carboxylate reacted with selenium dioxide in dioxane–water (30: 1) at 80?90°C to form methyl 5-(methoxycarbonyl)amino]-2-methyl-3-(2-oxoacetyl)-1H-indole-1-carboxylate whose condensation with o-phenylenediamine afforded methyl 2-methyl-5-(methoxycarbonyl)amino]-3-(quinoxalin-2-yl)-1H-indole-1-carboxylate. |
