反应详情

To a stirred solution of 2-[1-(2,5-dichlorophenyl)-cyclopentyl]-acetamidine hydrochloride (2=3) (2.0, 7.407 mmol) and (E)-2-benzyloxy-3-hydroxy-but-2-enedioic acid 4-tert-butyl ester (4) (3.422 g, 11.111 mmol) in methanol (50 mL) NaOMe (25% in methanol; 4.8 mL) was added dropwise at 0° C. and stirred at room temperature for 16 h. Silica thin layer chromatography was performed (40% ethyl acetate in hexane, Rf=0.6). The reaction mixture was quenched with HCl (1N; 5 mL), methanol was removed, the product was diluted with water and the mixture was extracted with ethyl acetate. The combined organic part was dried, the product was concentrated and the crude product was purified using a normal silica gel column using a gradient eluent of 10 to 40% ethyl acetate in hexane to get pure 5-benzyloxy-2-[1-(2,5-dichlorophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid tert-butyl ester (204) (2.1 g, 53.55%) as a yellow solid.

1. customThe reaction mixture was quenched with HCl (1N; 5 mL), methanol
2. customwas removed
3. additionthe product was diluted with water
4. extractionthe mixture was extracted with ethyl acetate
5. customThe combined organic part was dried
6. concentrationthe product was concentrated
7. customthe crude product was purified