Azonia-azulene salts. Part II. Further approaches to the synthesis of azepino[1,2-a]indolium salts

Abstract

Reduction, by hydrides, of 11-methylazepino[1,2-a]indol-10-one (2) and of the iron tricarbonyl complex (6) derived from it are described; reduction of the seven-memberd ring takes place as well as reduction of the carbonyl group. The action of hydrazine on the indolone (2) gave 3-methyl-2-(Δ²-pyrazolin-5-yl)acetylindole (12). The previously described 11H-azepino[1,2-a]indole has been shown to exist in the tautomeric 10H-form; and 11-methyl-10H-azepino[1,2-a]indole has also been prepared.