反应详情

24.8 g (0.20 mol) of 4-hydroxy-6-ethylpyrimidine are dissolved with 16.8 g (0.20 mol) of sodium hydrogen carbonate in 50 ml of water, and 32 g (0.20 mol) of bromine are slowly added dropwise at 8° to 10° C., with cooling. In the course of the addition, carbon dioxide evolves, and the product precipitates in the form of crystals. The product is separated off by extraction with ethyl acetate and crystallises out when the extract is concentrated using a rotary evaporator. There are obtained 22.7 g (55.9% of the theoretical yield) of a first fraction having a melting point of 177°-179° C. Concentration of the mother liquor yields a further 3.5 g (8.6%); m.p. 175°-177° C.

1. additionare slowly added dropwise at 8° to 10° C.
2. temperaturewith cooling
3. customthe product precipitates in the form of crystals
4. customThe product is separated off by extraction with ethyl acetate
5. customcrystallises out when the extract
6. concentrationis concentrated
7. customa rotary evaporator
8. customThere are obtained 22.7 g (55.9% of the
9. customtheoretical yield) of a first fraction
10. customConcentration of the mother liquor yields a further 3.5 g (8.6%)