Formation of a new 1,1,1 adduct in the reaction of malondialdehyde, n-hexylamine and alkanal under neutral conditions.

The reactions of malondialdehyde (MDA) with n-hexylamine (HA) in the presence of alkanals at a neutral pH were investigated. Two new compounds, 1,1,1 adduct (4a) and fluorescent compound (3a), were isolated from the reaction of MDA, HA and acetaldehyde. Compounds 4a and 3a were identified as 2-formyl-3-hexylamino-3-methylpropanal and 1-hexyl-5-hexyliminomethylene-4-methyl-1,4-dihydropyridine-3-carba ldehyde, respectively. Similar compounds (4b and 3b) were obtained from the reaction of MDA, HA and propanal. Compound 4 was obtained in a high yield. In addition, the reactivity of MDA towards phenylethylamine (PEA) in the presence or absence of alkanals was investigated. The results indicated that MDA was of low reactivity in the absence of alkanals at neutral pH. However, when alkanals coexisted, MDA showed high reactivity towards PEA.