Chlorosulfonic acid → 5-(2-Acetylamino-4-methyl-thiazol-5-yl)-2-methoxy-benzenesulfonyl chloride

Participants

Reaction Steps

To chlorosulfonic acid (25 ml, excess), cooled at −10° C., is added portionwise a suspension of N-[5-(4-methoxy-phenyl)-4-methyl-thiazol-2-yl]-acetamide (Example 31a) (1.0 g, 3.8 mmol) in DCM (10 ml). The temperature is kept below 0° C. throughout the addition. The reaction mixture is left to warm up to room temperature. After 2 hours, the reaction mixture is poured carefully onto ice (500 ml). Once the ice is melted, the aqueous layer is extracted with DCM (3×200 ml). The combined organic layers are washed with brine (150 ml), dried over MgSO4, filtered and concentrated to afford 5-(2-acetylamino-4-methyl-thiazol-5-yl)-2-methoxybenzene-sulfonyl chloride.

Provenance & Evidence