反应详情

To a stirred solution of 5-benzyloxy-2-(2,3-dichlorobenzyl)-6-hydroxypyrimidine-4-carboxylic acid tert-butyl ester (130) (10 g, 21.69 mmol) in a mixture of tetrahydrofuran-water (2:1, 90 mL) was added lithium hydroxide, monohydrate (4.55 g, 108.42 mmol). The mixture was refluxed for 18 h. After completion of the reaction, the volume was reduced by evaporation as much as possible, water was added, and the residue was washed with ethyl acetate to remove non-acidic impurities. The separated aqueous part was acidified with 2(N)HCl to bring the pH to approx. 5 to 6. The acidified aqueous part was extracted with dichloromethane, the separated organic part was dried over sodium sulfate and concentrated under reduced pressure to get 5-benzyloxy-2-(2,3-dichlorobenzyl)-6-hydroxypyrimidine-4-carboxylic acid (131) (7.5 g, 85.32%) as a white solid.

1. temperatureThe mixture was refluxed for 18 h
2. customAfter completion of the reaction
3. customthe volume was reduced by evaporation as much as possible, water
4. additionwas added
5. washthe residue was washed with ethyl acetate
6. customto remove non-acidic impurities
7. extractionThe acidified aqueous part was extracted with dichloromethane
8. dry with materialthe separated organic part was dried over sodium sulfate
9. concentrationconcentrated under reduced pressure