HCID 19907223, compound → HCID 10040931, compound

Participants

Reaction Steps

Titanium trichloride (256 ml, 15 wt % in 20-30 wt % HCl) was added in a steady stream to a stirred suspension of 5-(2,3-dicarboxypropylthio)-4-nitrothiophene-2-sulfonamide (21.8 g, 61.0 mmol) in water (128 ml) and acetic acid (128 ml). This mixture was stirred at ambient temperature for 18 hours and the yellow solid that precipitated was collected by filtration, washed with water and dried to yield 17.6 g. Chromatography over silica gel using chloroform/methanol/conc. aqueous ammonia (60:30:10; v/v/v) followed by recrystallization from water gave 3-carboxymethyl-2,3-dihydro-2-oxo-6-sulfamoyl-1H-thieno-[2,3-b][1,4]thiazine, mp 240° C.

Provenance & Evidence