反应详情

2-(4-Isocyanato-phenoxy)-propionic acid methyl ester 32 (20 g, 90.49 mmol) was added to ethylene glycol (40 ml) at room temperature. The reaction was exothermic and the temperature rose to 58° C. The mixture was allowed to cool and later stirred at room temperature for 16 hours. Water (150 ml) was added and crude 33 was extracted into chloroform, washed with water (2×50 ml), dried over sodium sulphate and distilled. Crude 33 was purified by column chromatography on silica gel using chloroform as eluant to get pure 33 (13 gr, 50.76%) as a syrup which crystallized in 48 hours as a white powder. M.p: 90.5-92.8° C.

1. customrose to 58° C
2. temperatureto cool
3. extractioncrude 33 was extracted into chloroform
4. washwashed with water (2×50 ml)
5. dry with materialdried over sodium sulphate
6. distillationdistilled
7. customCrude 33 was purified by column chromatography on silica gel