Electrochemical studies on haloamides. Part 4. Reactivity of haloacetamides and haloacetohydroxamates toward electrogenerated diethyl malonate anion

Abstract

The reactivity of haloacetamides and acetohydroxamates 1 and 2 toward electrogenerated diethyl malonate anion has been investigated. The course of the reaction primarily depends on the acidity of the amide NH group, which is mainly determined by the nature of the substituent, R, at the nitrogen atom. If this substituent is the same, the nature of the halogen atom also plays an important role. If the malonate anion can act as a base, products arising from foilow-up reactions of the conjugated base of the substrate are formed and their structure is dependent on R. In particular, β-lactams arising from a formal insertion of a malonate residue into the amide skeleton are obtained from haloacetanilides. When the substrate cannot be deprotonnated, the diethyl malonate anion behaves as a nucleophile provided that the leaving group is bromide. Chloro derivatives are rather stable toward malonate anion.