Reaction Steps
To a solution of 4-{[(benzyloxy)amino]carbonyl}phenyl acetate (18) (2.000 g, 7.0 mmol) and benzyl bromide (3.59 g, 21.0 mmol) in hexamethylphosphoric triamide (10 ml) Cs2CO3 (2.51 g, 7.7 mmol) was added and the reaction mixture was stirred at ambient temperature for 24 hours. The mixture was diluted with benzene (50 ml) and washed successively with water (2×30 ml), 2N HCl (30 ml), water (2×30 ml), brine (30 ml), and dried (Na2SO4). The solvent was evaporated and the residue was chromatographed on silica gel (100 g) with petroleum ether-benzene (1:1) and benzene-ethyl acetate (9:1) as eluents to give 4-{(benzyloxy)[(benzyloxy)imino]methyl}phenyl acetate (19) (1.743 g, 66%) as an oil, Rf 0.83 (toluene-ethyl acetate, 9:1), and 4-{[benzyl(benzyloxy)amino]-carbonyl}phenyl acetate (20) (0.744 g, 28%) as a white solid, Rf 0.48 (toluene-ethyl acetate, 9:1). (19): 1H NMR (DMSO-d6, HMDSO) δ: 2.24 (3H, s); 5.12 (2H, s); 5.32 (2H, s); 7.17 (2H, d, J=8.7 Hz); 7.25-7.54 (10H, m); 7.66 (2H, d, J=8.7 Hz). GC-MS, m/z (%): 375 (0.2), 268 (0.3), 253 (1), 227 (0.6), 211 (1.3), 196 (0.5), 180 (2.3), 163 (19.5), 121 (36), 107 (5.2), 91 (100), 77 (6), 65 (16). IR (film, cm−1): 1758, 1616, 1578, 1507. (20): 1H NMR (DMSO-d6, HMDSO) δ: 2.28 (3H, s); 4.72 (2H, s); 4.99 (2H, s); 6.88-7.10 (2H, m); 7.12-7.50 (8H, m); 7.22 (2H, d, J=8.0 Hz); 7.63 (2H, d, J=8.0 Hz). GC-MS, m/z (%):269 (36), 227 (27), 121 (100), 106 (25), 91 (46), 77 (14), 65 (26). IR (nujol, cm−1): 1756, 1663, 1604, 1578, 1507.
