Hydrochloric Acid → 2-(Benzo[1,2,5]thiadiazole-4-sulfonylamino)-4,5-dichlorobenzoic acid

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Reaction Steps

To a solution of 2-(benzo[1,2,5]thiadiazole-4-sulfonylamino)-4,5-dichloro-benzoic acid methyl ester (0.95 g, 2.3 mmol) in THF (21 mL) and water (7 mL) was added LiOH.H2O (0.38 g, 9.1 mmol). The biphasic mixture was stirred overnight at rt. The mixture was acidified with conc. HCl and extracted with DCM (3×). The combined organic layers were dried (MgSO4) and concentrated to provide 0.80 g (88%) of the pure acid as a white solid. 1H NMR (500 MHz, CDCl3): 11.07 (s, 1H), 8.41 (dd, J=7.0, 1.0, 1H), 8.27 (dd, J=8.8, 1.0, 1H), 8.01 (s, 1H), 7.94 (s, 1H), 7.75 (dd, J=8.8, 7.0, 1H).

Provenance & Evidence