Nitrosolysis of tertiary amines: piperidines, piperazines, bisdimethylaminoalkanes, and functionalized methyldialkylamines

Abstract

Preparative amounts of mono- and di-nitrosamines were obtained from aliphatic cyclic and acyclic tertiary monamines and diamines by treatment with dinitrogen tetraoxide in carbon tetrachloride at 0–45 °C. N-Methyl- and N-ethyl-piperidines (1) and (2) gave N-nitrosopiperidine (15), but N-isopropyl- and N-t-butyl-piperidines (3) and (4) did not. N-Methyl-, N-ethyl-, N-isopropyl- and N-t-butyl-N′- methylpiperazines (5)–(8) gave N,N′-dinitrosopiperazine (22)(in 90%, 81%, 55%, and 8% yields, respectively) and the diamine (8) also gave N-t-butyl-N′-nitrosopiperazine (23)(45%). The N′-nitroso and the N′-nitro derivatives of N-methylpiperazine were similarly converted into N,N′-dinitroso- and N-nitroso-N′-nitropiperazines (22)(45%) and (30)(53%). Bisdimethylaminoalkanes (Me₂N)₂(CH₂)_n(10)–(14) gave bismethylnitrosaminoalkanes [MeN(NO)]₂(CH₂)_n(24)–(27) and dimethylnitrosamine (28): n= 1(0%,90%); n= 2(68%,0%); n= 3(48%,43%); n= 4(41%,38%); n= 6(58%,35%). β-Dimethylaminopropionitrile (18), 1-methylnitrosamino-2-dimethylaminoethane (17), and α-dimethylaminoacetic acid (19) gave the corresponding nitrosoamines by replacement of an N-methyl group.