反应详情

A mixture of 5-bromo-2-chloropyrimidine (5.00 g, 0.0259 mol), phenol (3.16 g, 0.0336 mol), dibenzo-18-Crown-6 (0.47 g, 0.0013 mol) and ground potassium hydroxide (3.51 g, 0.0626 mol) in toluene (75 ml) was heated at reflux for 5 hours with azeotropic removal of water. The mixture was allowed to cool to ambient temperature and the solvent was removed under reduced pressure. The residue was partitioned between water and chloroform. The layers were separated and the aqueous phase was extracted with chloroform three times. The combined organic layers were dried over magnesium sulfate, filtered and evaporated. The residue was purified by flash column chromatography on silica using n-heptane/ethyl acetate (98:2) as an eluent to give 5-bromo-2-phenoxy-pyrimidine as a white solid (3.55 g, 0.0141 mol): 1H NMR (DMSO-d6, 400 MHz) 8.80 (s, 2H), 7.45 (t, 2H), 7.27 (t, 1H), 7.22 (d 2H); TLC (n-heptane/ethyl acetate=95:5) Rf 0.20.

1. temperaturewas heated
2. customthe solvent was removed under reduced pressure
3. customThe residue was partitioned between water and chloroform
4. customThe layers were separated
5. extractionthe aqueous phase was extracted with chloroform three times
6. dry with materialThe combined organic layers were dried over magnesium sulfate
7. filtrationfiltered
8. customevaporated
9. customThe residue was purified by flash column chromatography on silica