Lithium Hydroxide → 4-Fluoro-3-(morpholine-4-sulfonyl)benzoic acid

Participants

Reaction Steps

A solution of lithium hydroxide (1.56 g, 37.3 mmol) in water (5 mL) was added to a stirred solution of 4-fluoro-3-(morpholine-4-sulfonyl)-benzoic acid, methyl ester (Example 5, 2.26 g, 7.45 mmol) in methanol (50 mL) / water (10 mL) at 0° C. After 4 hours, the clear solution was quenched with aqueous hydrochloric acid (2M, 10 mL). Concentration in vacuo to remove the methanol afforded a white precipitate. Filtration and drying afforded the title compound as a white powder (1.89 g, 88% yield): 1HNMR (CDCl3) δ3.21 (td, J=7, 1.5 Hz, 4H), 3.75 (td, , J=7, 1.5 Hz , 4H), 3.98 (s, 3H), 7.28 (dd, J=18, 15 Hz, 1H), 8.28 (ddd, J=7, 5, 2 Hz, 1H), 8.51 (dd, J=7, 2 Hz, 1H): MS (ESI) [M−H]− at m/z 303.

Provenance & Evidence