3-Bromophenol → Methyl O-(3-bromophenyl)-N-triphenylmethyl-L-serinate

Participants

Reaction Steps

Methyl (2S)-3-hydroxy-2-(triphenylmethylamino)propanoate (5.2 g , 14.4 mmol, 1 equiv; prepared according to Baldwin, J. E.; Spivey, A. C.; Schofield, C. J.; Sweeney, J. B. Tetrahedron 1993, 49, 6309) and triphenylphosphine (4.2 g, 15.8 mmol, 1.1 equiv) were dissolved in toluene (25 mL) at rt (room temperature). The reaction mixture was stirred for 30 min followed by addition of 3-bromo phenol (3.2 g, 18.7 mmol, 1.3 equiv) and DEAD (diethylazo dicarboxylate; 2.8 g, 15.8 mmol, 1.1 equiv) at rt. The reaction mixture was stirred at ambient temperature for 15 h while a white precipitate formed. The precipitate was filtered off and the solvents of the filtrate were removed in vacuuo. The remaining crude product was purified by flash chromatography (cyclohexanes/ethyl acetate 95:5) to give a white solid (5.2 g, 67.3%). 1H NMR (CDCl3, 200 MHz) δ 7.65-7.55 (m, 4 H); 7.41-7.12 (m, 9H); 6.70 (d, 2H); 4.20 (dd, 1H); 4.00 (dd, 1H); 3.75-3.60 (m, 1H); 3.73 (s, 3H); 2.87 (d, 1H).

Provenance & Evidence