Thiocarbamoylation of sulfonamides with isothiocyanates

Abstract

1,3-Thiazetidines 3a-c , thiazolidines 3d-f , perhydro-1,3-thiazine 3g and perhydro-1,3-thiazepine 3h , respectively, were prepared by alkylation of sodium salts 2 with dihaloalkanes. Isothioureas 4 and 5 were obtained using analogous conditions. Reaction of p -toluenesulfonamide with sodium hydride/phenyl isothiocyanate and subsequent alkylation with ethyl bromoacetate formed S -ethoxycarbonylmethyl-isothiourea 6 or thiazolidone 7 . Reaction of 6 with thiacumulenes gave 1,3-dithiolane 8 or ketene- S,N -acetal 9 .