反应详情

5-(Benzyloxy)-2-(2-bromobenzyl)-6-oxo-3,6-dihydro-pyrimidine-4-carboxylic acid tert-butyl ester (67) (2.69 g, 5.71 mmol, Eq: 1.00) and LiOH (683 mg, 28.5 mmol, Eq: 5) were stirred in tetrahydrofuran (18 ml)/water (9.00 ml) under reflux for 6 h, at room temperature overnight and again to reflux for 3 h. Then the solvent was mostly removed. The remaining oil was diluted with water and extracted with ethyl acetate. The aqueous layer was cooled in an ice bath and was acidified with HCl conc. Precipitate formed, was collected by filtration, washed with water and dried to afford 5-(benzyloxy)-2-(2-bromobenzyl)-6-oxo-3,6-dihydro-pyrimidine-4-carboxylic acid (68) (2.14 g, 5.15 mmol, 90.3% yield) as a white solid.

1. temperatureagain to reflux for 3 h
2. customThen the solvent was mostly removed
3. additionThe remaining oil was diluted with water
4. extractionextracted with ethyl acetate
5. temperatureThe aqueous layer was cooled in an ice bath
6. customformed
7. filtrationwas collected by filtration
8. washwashed with water
9. customdried