Hydrochloric Acid → 2H-1,2,4-Benzothiadiazine-3-acetic acid, 7-[(methylsulfonyl)amino]-, 1,1-dioxide

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Reaction Conditions

Reaction Steps

N-(4-methanesulfonylamino-2-sulfamoyl-phenyl)-malonamic acid methyl ester (prepared as described in Example 1g, 1.35 kg, 3.69 mol) was added to 3.8 wt. % aqueous sodium hydroxide solution (14.0 kg). The resulting mixture was stirred at 23° C. for 30 h, and was then cooled to 0° C. A 2.0M aqueous hydrochloric acid solution (9.72 L) was slowly added, stirring at 0° C. was continued for 30 min, and the mixture was then filtered. The solid was washed with water (1.4 L), and was then slurried in a mixture of methanol (1.4 L) and diethyl ether (2.7 L). After filtration, the solid was washed with diethyl ether (2×1.4 L) and was further dried in vacuo at 23° C. to afford the desired product, (7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetic acid (1.07 kg, 3.21 mol, 87%), as a light brown solid.

Provenance & Evidence