4-Fluorobenzenesulfonyl chloride → (R)-2-(4-fluoro-benzenesulfonylamino)-4-methyl-pentanoic acid

Participants

Reaction Steps

A mixture of 4-fluoro-benzenesulfonyl chloride (1.65 g, 0.00848 mol), (R)-2-amino-4-methyl-pentanoic acid (1.233 g, 0.009398 mol), and sodium carbonate (1.91 g, 0.0180 mol) in water (15 mL) was stirred at room temperature for 5 days. The solution was filtered, and the filtrate was acidified with concentrated hydrochloric acid to pH=4. The mixture was extracted with ethyl acetate. The extract was washed with saturated sodium chloride, dried (MgSO4), and rotary evaporated to a yellow oil. The oil was chromatographed on silica gel (320 g, 230-400 mesh) eluting with dichloromethane-methanol (10:1, 10×300 mL). Fractions containing product were combined and rotary evaporated to give a pale yellow oil. The oil was dried in vacuo; yield 1.44 g (59%).

Provenance & Evidence