反应详情

A mixture of 5-benzyloxy-6-hydroxy-2-(8-phenyl-1,4-dioxa-spiro[4.5]dec-8-ylmethyl)-pyrimidine-4-carboxylic acid tert-butyl ester (269) (850 mg, 1.60 mmol), LiOH.H2O (670 mg, 15.96 mmol) in tetrahydrofuran-water (5:1, 48 mL) was refluxed for 20 h while silica thin layer chromatography was performed (methanol:dichloromethane=1:9, Rf=0.1). Tetrahydrofuran was removed from the reaction mixture in vacuo and the residue was diluted with water (25 mL), cooled in ice water, neutralized to about pH 7 with 1N aqueous HCl and extracted with ethyl acetate (2×50 mL). The combined organic parts were washed with brine (25 mL), dried and concentrated in vacuo to get pure 5-benzyloxy-6-hydroxy-2-(8-phenyl-1,4-dioxa-spiro[4.5]dec-8-ylmethyl)-pyrimidine-4-carboxylic acid (270) (700 mg, 92.05%) as a yellow solid.

1. temperaturewas refluxed for 20 h while silica thin layer chromatography
2. customTetrahydrofuran was removed from the reaction mixture in vacuo
3. additionthe residue was diluted with water (25 mL)
4. temperaturecooled in ice water
5. extractionextracted with ethyl acetate (2×50 mL)
6. washThe combined organic parts were washed with brine (25 mL)
7. customdried
8. concentrationconcentrated in vacuo