4-Fluorobenzenesulfonyl chloride → HCID 21697167, compound

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Reaction Steps

A mixture of isobutylamino-acetic acid, ethyl ester hydrochloride (0.359 g, 0.00183 mol) in 6 M hydrochloric acid (10 mL) was refluxed for 20 hours and allowed to cool. The mixture was made basic with 50% wt/wt sodium hydroxide and 1 M sodium hydroxide to pH=5, and the volatiles were rotary evaporated. The residue was triturated 3 times with boiling methanol, and the triturates were combined and rotary evaporated. The residue was triturated 3 times with hot acetic acid, and the triturates were combined and rotary evaporated. The residue was dissolved in water and freeze-dried to give a white solid. This solid was combined with 4-fluoro-benzenesulfonyl chloride (0.3334 g, 0.001713 mol) and sodium carbonate (0.547 g, 0.00516 mol) in water, and the mixture was stirred at room temperature for 3 days. The mixture was acidified with concentrated hydrochloric acid and extracted with ethyl acetate. The extract was dried (MgSO4) and rotary evaporated to a white solid. The solid was chromatographed on silica gel (15 g, 230-400 mesh) eluting with dichloromethane-methanol (10:1, 10×15 mL). Fractions containing product were combined and rotary evaporated to give a white solid. The solid was dried in vacuo; yield 0.32 g (64% overall). 1H-NMR (DMSO-d6): δ7.85 (m, 2H), 7.39 (m, 2H), 3.91 (s, 2H), 3.32 (br s, H2O), 2.94 (d, 2H), 1.77 (m, 1H), 0.79 (d, 6H).

Provenance & Evidence