Cesium carbonate → HCID 86612155, compound

Participants

Reaction Steps

A solution of 4-fluorobenzenesulfonic acid 2-(cyclopropanecarbonylamino)-benzothiazol-6-yl ester (example 7) (0.352 mmol, 138 mg), 4-amino-TEMPO (0.387 mmol, 66 mg) and cesium carbonate (0.352 mmol, 114 mg) in 3.5 ml of dimethylsulfoxide is stirred for 24 hours. 4-Amino-TEMPO is added twice (2 times 66 mg) after 24 and 48 hours. After 48 hours, the reaction is placed at room temperature for 48 hours. The solution is then diluted with water, extracted with ethyl acetate, washed with saturated sodium chloride solution and dried over sodium sulfate, and then evaporated to dryness, to give 258 mg of crude product. This product is purified by flash chromatography on a cartridge of 5 g of silica. The eluents used are, respectively, dichloromethane and then dichloromethane with 1% of 7M 0.01% ammoniacal methanol. 28 mg of 4-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-ylamino)benzenesulfonic acid 2-(cyclopropanecarbonylamino)benzothiazol-6-yl ester are obtained in a yield of 14%.

Provenance & Evidence