Tetrahydrofuran → 3-(4-Nitrobenzoyl)-1,3-thiazolidine-2-thione

To a solution of 4-nitrobenzoyl chloride (3.1 g) and tetrahydrofuran (50 ml) were added 1,3-thiazolidine-2-thione (2.0 g) and triethyl amine (2.5 g). The mixture was stirred at 50° C. for 30 minutes under nitrogen atmosphere. The reaction mixture was filtered and the solvent was removed at a reduced pressure. To the residue was added water, and the solution is extracted with dichloromethane. The extract was washed with a saturated aqueous solution of sodium chloride and dried with use of Glauber's salt. The solvent was distilled off and the resulting crystals were purified by silica gel column chromatography (developer: dichloromethane) and recrystallized from dichloromethane to obtain 3.3 g of the desired compound as yellow needle crystals (yield 82.5%).