Lithium Hydroxide → HCID 57617823, compound

Participants

Reaction Steps

To a solution of methyl 4-(4-fluorophenylsulfonyl)-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxylate (1.779 g, 4.84 mmol) in THF (12 mL) and water (6 mL) was added LiOH (0.6096 g). The reaction was allowed to stir at room temperature for 16 hours. LCMS analysis identified the product as the predominant component of the reaction mixture. The solvent was removed under reduced pressure. The resulting aqueous solution was acidified with 1N HCl to provide a white precipitate. The aqueous layer was extracted with DCM until the acid was no longer detected in the organic wash layer. The combined organics were washed with H2O and dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The mixture was purified by flash chromatography using a gradient elution of hexane with 0-95% ethyl acetate doped with 1% AcOH. The product, 4-(4-fluorophenylsulfonyl)-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxylic acid (1.108 g, 3.14 mmol, 65% yield), was isolated as off-white solid. LCMS (+ESI) m/z=354.0 [M+H]+.

Provenance & Evidence