64039-36-7

4025-75-6

The general procedure for the synthesis of (4-nitrophenyl)methanesulfonyl chloride from 4-nitrophenylaminosulfate methyl ester hydrochloride is as follows: 1. the alkyl halide (or sulfate) (5 mmol) was heated with thiourea (0.381 g, 5 mmol) in ethanol (5 mL) at reflux for 1 hour. 2. Upon completion of the reaction, the solvent was removed under vacuum and the residue was washed with ether (3 x 5 mL) to afford the corresponding S-alkyl isothiourea salt as a white solid in near quantitative yield. 3. Without further purification, the resulting S-alkylisothiourea salt was transferred to a three-necked round-bottomed flask equipped with a thermometer and a charging funnel and placed in an ice bath. 4. Water (0.45 mL) and acetonitrile (10 mL) were added to the flask to form a vigorously stirred mixture. 5. A solution of tert-butyl hypochlorite (t-BuOCl, 2.86 mL) in acetonitrile (5 mL) was added slowly and dropwise while maintaining an internal temperature of 0-20°C. The solution was then mixed with water (0.45 mL) and acetonitrile (10 mL). 6. After the dropwise addition was completed, the reaction mixture was continued to be stirred for 30 minutes. 7. Upon completion of the reaction, the solvent was removed under vacuum and ether (15 mL) was added to dissolve the residue. 8. The ether layer was washed with water (2 x 10 mL) and dried with anhydrous sodium sulfate (Na2SO4). 9. 9. After drying, the ether solution is concentrated in vacuum to give high purity (4-nitrophenyl)methanesulfonyl chloride. 10. The product can be further purified by recrystallization from a mixed petroleum ether-ethyl acetate solvent.