Reactions concerned in tertiary amine-N-oxides. I. Reactions of aliphatic and cyclic amine-N-oxides with ethyl malonate

Abstract

It was considered that the oxygen atom in amine N-oxides would serve as an oxidation agent, and reactions were carried out on acyclic or cyclic amine N-oxides alone or with addition of pyridine N-oxide and ethyl malonate (I), with platinated palladium-carbon catalyst, by heating at 80-110° for ca. 8 hr. The reaction products obtained were tetraethyl propanetetracarboxylate (II) as a neutral component, and a compound (III), formed by introduction of -CH2COOEt group into α-position of amine-nitrogen, as a basic component (Tables I and II). In general, II is the main product from acyclic aliphatic amine N-oxides (yield, 7-34%) and III is formed in only a trace, while III is a main product (yield, 6.5-27%) from cyclic aliphatic amines, with less of II (yield, less than 2%).