反应详情

To a mixture of 2-(4-nitrophenoxy)-propionic acid 29 (25 g, 118.5 mmol) and 2-(4-nitrophenoxy)propionic acid 2-hydroxyethyl ester 30 (25 g, 108 mmol) in anhydrous dichloromethane (625 ml) under nitrogen atmosphere was added dropwise a solution of 1,3-dicyclohexyl carbodiimide (40 g, 194 mmol) in anhydrous dichloromethane (250 ml). The reaction mixture was stirred at room temperature for 8 hours. The solids were filtered off and dichloromethane distilled off to get crude 31. The crude 31 was purified by column chromatography on silica gel using hexane as eluant to get pure 31 (17 g, 35.1%) as a white powder with an m.p. between 117.5-120.5° C.

1. filtrationThe solids were filtered off
2. distillationdichloromethane distilled off
3. customto get crude 31
4. customThe crude 31 was purified by column chromatography on silica gel