Cyclic polysulphur compounds from the iron-catalysed reaction of m-dimethoxybenzene with disulphur dichloride

Abstract

The iron-catalysed reaction of m-dimethoxybenzene with sulphur chlorides (SCl₂ and S₂Cl₂) has been investigated both neat and in dilute solution. Neat reaction gives linear polysulphides (3), bis-(2,4-dimethoxyphenyl) sulphide (4), and 1,3-dimethoxy-4,6-bis-(2,4-dimethoxyphenylthio)benzene (5), while in dilute solution the formation of 5,7,14,16-tetramethoxy-1,2,3,10,11,12-hexathia[3.3]metacyclophane (1) and 4,6,12,14,20,22-hexamethoxy1,2,9,10,17,18-hexathia[2.2.2]metacyclophane (2) is observed. Compounds (1) and (2) were also obtained by independent synthetic routes. Their ¹H n.m.r. and mass spectra are discussed.