Chlorosulfonic acid → 5-[2-(3-Ethyl-ureido)-4-methyl-thiazol-5-yl]-2-methoxy benzenesulfonylchloride

Participants

Reaction Conditions

Reaction Steps

A suspension of 1-ethyl-3-[5-(4-methoxy-phenyl)-4-methyl-thiazol-2-yl]urea (Example 28c) (1.0 g, 3.44 mmol) in dichloromethane (15 ml) is added portionwise to chlorosulfonic acid (25 ml, excess) cooled at −10° C. The temperature is kept below 0° C. throughout the addition. The reaction mixture is left to warm up to room temperature. After 3 hours, the reaction mixture is poured carefully onto ice (2 litres). Once ice is melted, the aqueous layer is extracted with dichloromethane (DCM) (3×200 ml). The combined organic layers are washed with brine, dried over MgSO4, filtered and concentrated to afford 5-[2-(3-ethyl-ureido)-4-methyl-thiazol-5-yl]-2-methoxy benzenesulfonylchloride.

Provenance & Evidence