Synthetical applications of activated metal catalysts. XX. The action of degassed Raney nickel on some N-Alkyl-o-alkylanilines

Abstract

At temperatures not exceeding 230° degassed Raney nickel caused stepwise dealkylation of the o-alkyl groups of o-propylaniline, o-ethylaniline, N-methyl-o-ethylaniline, and N-ethyl-o-toluidine. N-Alkyl groups were removed simultaneously. Indole was isolated from o-propylaniline, o-ethylaniline, and N-methyl-o-ethylaniline. 2-Methylindole was obtained from o-propylaniline, and 3-methylindole was isolated from N-methyl-o-ethylaniline. N-allylaniline and o-propylaniline formed traces of 3-methylindole; N-ethyl-o-toluidine gave traces of indole and 2-methylindole. Indoline was mostly dehydrogenated but it also underwent dealkylation. Small amounts of 2-alkylcyclohexanones were isolated from o-propylaniline, o-ethylaniline, and N-methyl-o-ethylaniline. The last amine also formed carbazole.