反应详情

To compound 4 (0.8235 g, 2.71 mmol) in 30 ml of dry acetonitrile, methyl bromoacetate (1.08 g, 7.06 mmol) was added at room temperature. The mixture was stirred for 2 h. Evaporation of acetonitrile gave a crude product. The crude product was dissolved in a small volume of methylene chloride and then poured into 100 ml of dry ethyl ether to precipitate. This procedure was repeated three times to obtain Compound (a) as pure product (0.9912 g, 80%). White powder, m.p.: 192-194° C. Analysis for C21H30BrNO5. Calcd: C, 55.27; H, 6.63; N, 3.07. Found: C, 55.11; H, 6.59; N, 3.03. 1H NMR (CDCl3, 500 MHz): 1.23-1.29, 1.31-1.37, 1.41-1.47, 1.53-1.67 [8H, m, (CH2)4], 2.18-2.23, 2.73-2.80, 4.04-4.16, 4.21-4.25 (6H, m, CH2NCH2CH2), 2.85 [1H, p, CHC(OH)], 3.57 (3H, s, NCH3), 3.80 (3H, s, CO2CH3), 4.66, 4.85 (2H, 2dd, CH2CO2), 5.27 (1H, s, OH), 5.52 (1H, m, CO2CH), 7.25-7.28, 7.32-7.35, 7.57-7.59 (5H, m, Ph) ppm.

1. customEvaporation of acetonitrile
2. customgave a crude product
3. customto precipitate