Lithium Hydroxide → 3-[(2-tert-Butoxy-2-oxo-1-phenyl-ethyl)sulfamoyl]benzoic acid

To a stirring solution of methyl 3-[(2-tert-butoxy-2-oxo-1-phenylethyl)-sulfamoyl]benzoate (2.2 g, 5.4 mmol) in tetrahydrofuran (33.7 mL) and methanol (33.7 mL) was added 1.0 N aqueous lithium hydroxide (13.5 mL, 13.5 mmol) in one portion. The reaction mixture was stirred for 18 hours at ambient temperature, after which time the mixture was concentrated under reduced pressure. The resulting crude was partitioned between ethyl acetate (20 mL) and water (40 mL); the resulting aqueous was acidified with concentrated sulphuric acid (c. 1.0 mL) and washed with ethyl acetate (2×20 mL). The organic phases were combined, dried over magnesium sulfate and concentrated under reduced pressure to yield the title compound as a white solid (1.21 g, 57%).