反应详情

To a stirred solution of 2-(2-bromo-4-chlorophenyl)-acetamidine hydrochloride (375) (7 g, 24.823 mmol) and 2-benzyloxy-3-hydroxy-but-2-enedioic acid 4-tert-butyl ester 1-methyl ester (4) (11.47 g, 37.23 mmol) in methanol (100 mL) was dropwise added sodium methoxide (16.1 mL) (25% in methanol) at 0° C. The reaction mixture was allowed to warm to room temperature and stirred for 16 h while silica thin layer chromatography was performed (50% ethyl acetate in hexane; Rf=0.5). The reaction mixture was quenched with 1N HCl (5 mL) and the methanol was removed under reduced pressure to yield a residue which was diluted with water (200 mL) and extracted with ethyl acetate (2×250 mL). The combined organic parts were dried and concentrated. The obtained crude product was purified by normal silica (100-200 mesh) column to get 5-benzyloxy-2-(2-bromo-4-chlorobenzyl)-6-hydroxypyrimidine-4-carboxylic acid tert-butyl ester (376) (6.02 g, 47.95%) as a white solid.

1. customat 0° C
2. customThe reaction mixture was quenched with 1N HCl (5 mL)
3. customthe methanol was removed under reduced pressure
4. customto yield a residue which
5. extractionextracted with ethyl acetate (2×250 mL)
6. customThe combined organic parts were dried
7. concentrationconcentrated
8. customThe obtained crude product
9. customwas purified by normal silica (100-200 mesh) column