反应详情

To a mixture of HCl-salt of 2-(1-phenyl-cyclohexyl)-acetamidine (254) (2.0 g, 7.91 mmol) and (E)-2-benzyloxy-3-hydroxy-but-2-enedioic acid 4-tert-butyl ester 1-methyl ester (9) (3.66 g, 11.86 mmol) in methanol (50.0 mL) was added sodium methoxide (1.28 g, 23.73 mmol, 25% in methanol) at 0° C. Then the reaction mixture was allowed to warm up to room temperature and was stirred for 16 h. After completion of the reaction, the solvent was reduced and the crude product was dissolved in dichloromethane and the resultant mixture extracted with dichloromethane. The organic layer was washed with 1N HCl and with water and brine. It was then dried over Na2SO4 and concentrated. The crude product was purified by normal silica gel column chromatography (using 10% ethyl acetate in hexane) to get 5-benzyloxy-6-hydroxy-2-(1-phenyl-cyclohexylmethyl)-pyrimidine-4-carboxylic acid tert-butyl ester (255) (3.2 g, 85.0%) as a yellowish thick liquid which turned into a solid after storing at room temperature.

1. customAfter completion of the reaction
2. extractionthe resultant mixture extracted with dichloromethane
3. washThe organic layer was washed with 1N HCl and with water and brine
4. dry with materialIt was then dried over Na2SO4
5. concentrationconcentrated
6. customThe crude product was purified by normal silica gel column chromatography (using 10% ethyl acetate in hexane)