The reaction between oximes and sulphinyl chlorides: a ready, low-temperature radical rearrangement process

Abstract

The reaction of ketoximes and amidoximes with sulphinyl chlorides at low temperatures produces the thermally unstable O-sulphinylated oximes (I), which have been characterised by ¹H and ¹³C n.m.r. spectroscopy. At higher temperatures, the products are the thermally stable N-sulphonylimines (II), produced by thermal rearrangement of compounds (I). The rearrangement of (I) to (II) has been shown, by means of e.s.r., ¹³C CIDNP, and kinetic studies, to involve homolytic N–O bond cleavage to give iminyl and sulphonyl radicals followed by radical recombination with N–S bond formation.