反应详情

6-Amino-2-(4-chloro-2-fluoro-3-methoxyphenyl)-5-chloropyrimidine-4-carboxylic acid methyl ester (320 mg, 0.92 mmol, see U.S. Pat. No. 7,300,907 B2 for preparation) was dissolved in 10 mL 1M H2SO4 plus 4 mL acetonitrile, warmed to 75° C. and treated in portions with sodium nitrite (690 mg, 10 mmol) over 30 minutes. After stirring for 10 minutes more the mixture was cooled and the solid product was collected by filtration, washed well with water, and dried under vacuum at 80° C. to give 170 mg (53% yield) of 6-hydroxy-2-(4-chloro-2-fluoro-3-methoxyphenyl)-5-chloropyrimidine-4-carboxylic acid methyl ester MP 215-217° C.; MS m/z 346; 1H NMR (DMSO-d6): δ 7.47 (m, 2H), 3.94 (s, 3H), 3.91 (s, 3H), 3.34 (br s, 1H).

1. temperaturewas cooled
2. filtrationthe solid product was collected by filtration
3. washwashed well with water
4. customdried under vacuum at 80° C.