4-Methylmorpholine → (S)-2-(4'-Bromo-biphenyl-4-sulfonylamino)-3-methyl-butyric Acid Tert-butyl Ester

Participants

Reaction Steps

To a solution of L-valine-tert-butyl ester hydrochloride (15.7 g, 0.075 mol) and N-methylmorpholine (15.2 g, 0.15 mol) in dichloromethane (250 mL) was added in one portion 4'-bromobiphenyl-4-sulfonyl chloride (25 g, 0.075 mol). The solution was stirred at room temperature for 16 hours, filtered, and the filtrate was concentrated in vacuo. The residue was diluted with ethyl acetate (250 mL) and washed with HCl (1N), saturated sodium chloride, and dried over magnesium sulfate. The drying agent was filtered, and the filtrate was concentrated in vacuo leaving a cream-colored solid. The crude product was purified using silica gel chromatography (elution with chloroform) to give the title compound (21.2 g, 60%) as a white solid.

Provenance & Evidence