Lawesson's reagent → HCID 19907226, compound

Participants

Reaction Steps

A mixture of 2,3-dihydro-2,4,4-trioxo-6-sulfamoyl-1H-thieno[2,3-b][1,4]thiazine (5 g) and Lawesson's reagent (3.8 g) in dimethoxyethane (25 ml) was heated under reflux for seven hours. The solvent was removed under reduced pressure and the residue was chromatographed over silica gel with chloroform/methanol/acetic acid (90:8:2, v/v/v) as the eluent. The fractions containing the desired product were combined and evaporated to dryness to yield 1.4 g. Two recrystallizations from ethyl acetate/hexane gave pure 2,3-dihydro-4,4-dioxo-6-sulfamoyl-2-thiono-1H-thieno[2,3-b][1,4]thiazine, mp 219°-221° C.

Provenance & Evidence