Intramolecular Bromoamination. Part I

Abstract

The addition of bromine to 2,2-diphenyl-4-pentenylamine (8a) resulted in the formation of 2-bromomethyl-4,4-diphenylpyrrolidine hydrobromide (10a), the structure of which was established by its mass spectrum and other properties. Analogous products were obtained from the corresponding methyl secondary amine and two methyl-substituted primary amines.The bromomethylpyrrolidines 10a and 10c gave the aziridines 11a and 11b on treatment with sodium hydride in DMF. Dry hydrogen bromide converted the unsubstituted aziridine 11a to 3,3-diphenyl-5-bromopiperidine hydrobromide (12a). Liberation of the methyl substituted bromomethylpyrrolidine 10b from the hydrobromide salt resulted in the spontaneous transformation to a single 2-methyl-3-bromopiperidine (12b) of unestablished stereochemistry.