反应详情

温度

75 °C

A mixture of 4-chloro-8-(cyclopentyloxy)-7-methoxy-2H-chromen-2-one (170 mg, 0.58 mmol, Example 7, Step 1), glycine ethyl ester•HCl (97 mg, 0.69 mmol), triethylamine (0.2 mL, 1.4 mmol), and ethanol (2 mL) was heated at 75° C. in a sealed vial for 30 h. The reaction was allowed to cool to rt, concentrated, and purified by silica gel chromatography (3:2→1:4; hexanes:ethyl acetate) to give ethyl 2-(8-(cyclopentyloxy)-7-methoxy-2-oxo-2H-chromen-4-ylamino)acetate: 1H NMR (400 MHz, DMSO-d6): δ 7.93 (t, 1H), 7.68 (d, 1H), 7.08 (d, 1H), 4.92 (s, 1H), 4.80 (m, 1H), 4.13 (q, 2H), 4.10 (d, 2H), 3.86 (s, 3H), 1.90-1.45 (m, 8H), 1.20 (t, 3H); MS (ESI): 361.9.

1. temperatureto cool to rt
2. concentrationconcentrated
3. custompurified by silica gel chromatography (3:2→1:4; hexanes:ethyl acetate)