反应详情

温度

60 °C

To a mixture of 6-[4-(2-hydroxyethoxycarbonylamino)phenoxy]hexanoic acid methyl ester 19 (5 g, 15.38 mmol) in toluene (50 ml) was added 6-(4-isocyanatophenoxy)-hexanoic acid methyl ester 18 (4 g, 15.2 mmol) at room temperature and heated to 60° C. for 2 hours. Toluene was distilled and water (50 ml) was added. The solid was filtered and dried to give crude 20, which was purified by column chromatography on silica gel using chloroform as eluant to get pure 20 (8.5 g, 94%) as a white powder with an m.p. between 118-120.5° C.

1. distillationToluene was distilled
2. additionwater (50 ml) was added
3. filtrationThe solid was filtered
4. customdried
5. customto give crude 20, which
6. customwas purified by column chromatography on silica gel