Abstract
Malondialdehyde (MDA) reacted with secondary amines (dimethylamine, diethylamine, piperidine, pyrrolidine and morpholine) at 37° under mild acidic or neutral conditions to yield β-dialkylaminoacroleins (1-5) of trans, s-trans conformation. The optimal pH of the reaction was 3-5, and the yields were 15-55% in a 6 hr incubation. The acroleins (1-5) were unstable under acidic and alkaline conditions, and produced a pink color on reaction with 2-thiobarbituric acid. β-Dimethylaminoacrolein (1) could be readily nitrosated in the acidic pH range to produce N-nitrosodimethylamine, and the rate of nitrosamine formation from 1 at pH 5.0 was much higher than that from dimethylamine ; this is consistent with earlier observations of the stimulating effect of MDA on nitrosamine formation.
