Methanol → N-(tert-Butoxycarbonyl)-2(S)-phenylglycinbromide

Participants

Reaction Steps

To a stirred solution of N-(tert-butoxycarbonyl)-2(S)-phenylglycinol (1.67 g, 7.0 mmol) and carbon tetrabromide (5.0 g, 15 mmol) in 35 mL of anhydrous ether was added a solution of triphenylphosphine (4.09 g, 15.4 mmol) in 25 mL of anhydrous ether at 0° C. The reaction mixture was stirred at room temperature for 12 h. The ether suspension was filtered with a sintered glass funnel containing a bed of celite. The ether filtrate was concentrated under reduced pressure to give a crude product. Flash chromatography (silica gel, 0.2% MeOH, 0.004% Et3N, 40% methylene chloride in hexane) afforded 1.68 g of product (80% yield) as a white solid, mp 108-109° C. 1H NMR (CDCl3) δ 1.431 (s, 9H, tert-Bu) 3.664 (s, 2H, BrCH2), 5.001 (s, 1H, NH), 5.272 (d, 1H, J=7.8 Hz, benzyl), 7.25-7.38 (m, 5H, aryl); 13C NMR (CDCl3) δ 28.24 (CH3) 37.00 (BrCH2), 54.80 (CMe3), 79.98 (NCH), 126.35 (aromatic), 127.88, 128.59, 139.40, 154.91.

Provenance & Evidence