Chemical Studies on Amino-Carbonyl Reaction

Part III. Formation of Substituted Pyrrole-2-aldehydes by Reaction of Aldoses with Alkylamines

Abstract

When N-n-butyl-D-xylosylamine was heated with acetic acid in methanol at 55_??_70°C, it decomposed to N-n-butylpyrrole-2-aldehyde, ^** through 3-deoxy-D-pentosulose as an intermediate. D-Xylose and methylamine in neutralized aqueous solution at 65_??_100°C also formed N-methylpyrrole-2-aldehyde. N-n-Butyl-L-rhamnosylamine, in a mixture of methanol and acetic acid, formed the corresponding pyrrolealdehyde, 1-n-butyl-5-methylpyrrole-2-aldehyde, at the almost same rate as did N-xyloside. On the contrary, N-n-butyl-D-glucosyl-amine, under the same condition, did not form any detectable amount of the corresponding pyrrolealdehyde, but formed complicated products. A formation mechanism of the pyrrolealdehydes from 3-deoxyosulose and amine was proposed.