Lawesson's reagent → 1-[4-(1-Hexahydroazepinyl)benzenesulphonyl]-2-pyrrolidinethione

Participants

Reaction Steps

A mixture comprising 12.53 g of 1-[4-(1-hexahydroazepinyl)benzenesulphonyl]-2-pyrrolidinone, prepared as in Example 18 of the European Patent published under No. 0,033,578, and 7.5 g of Lawesson reagent (or 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulphide) in 250 cm3 of tetrahydrofuran is heated to reflux for 48 hours. The mixture is allowed to return to room temperature and is evaporated to dryness, and the residue is chromatographed on silica (eluant: benzene). 7.3 g of product are recovered. M.p. 173°-175° C. After crystallization in a chloroform/n-hexane mixture, 6 g of expected pure product are obtained. M.p. 176°-178° C.

Provenance & Evidence