Methanol → HCID 86592632、化合物

反応式

[OH:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([N:9]2[C:13](=[O:14])[CH2:12][CH:11]([C:15]([OH:17])=[O:16])[CH2:10]2)=[CH:5][CH:4]=1.[CH3:18]O>S(=O)(=O)(O)O.COC(OC)(C)C>[CH3:18][O:16][C:15]([CH:11]1[CH2:12][C:13](=[O:14])[N:9]([C:6]2[CH:5]=[CH:4][C:3]([O:2][OH:1])=[CH:8][CH:7]=2)[CH2:10]1)=[O:17]

参加物

実験手順

In a 10 1 4-necked flask equipped with a reflux condenser, a thermometer, and a mechanical stirrer, the crude (RS)-1-(4-hydroxyoxy-phenyl)-5-oxo-pyrrolidine-3-carboxylic acid is dissolved in a mixture of 5000 ml of methanol, 24 ml of concentrated sulfuric acid and 400 ml of 2,2-dimethoxypropane and stirred under reflux during 2 h. For the working-up, the reaction solution is reduced to half of its volume by distillation, then transferred into a 20 1 vessel. Under stirring at 40° C., a mixture of 2500 ml of water/ice (1:1) is added. Crystallisation started immediately, and, thereupon, the fine white crystals are collected on a filter funnel. They are washed with total 2000 ml of cold water until the filtrate, at the beginning brownish-rose, becomes colorless and neutral. The well pressed and pre-dried product from the filter funnel is dried under reduced pressure to yield 980 g (84% of theory, 2 steps) of the (RS)-1-(4-hydroxyoxy-phenyl)-5-oxo-pyrrolidine-3-carboxylic acid methyl ester as a white solid; MS: m/e=234 (M+H)+.