反应详情

温度

50 °C

A 22% solution of sodium ethoxide in ethanol (53 mL, 165 mmol) was added dropwise to a magnetically stirred suspension of tert-butylcarbamidine hydrochloride (20.0 g, 146 mmol) in ethanol (100 mL). When the addition was complete, the yellow suspension was warmed to 50° C., the heating mantle was removed, and a solution of mucobromic acid (15.7 g, 61 mmol) in ethanol (50 mL) was added dropwise at a rate which did not allow the temperature to exceed 55° C. When this addition was complete, a 22% solution of sodium ethoxide in ethanol (32 mL, 98 mmol) was added dropwise, then the mixture was allowed to cool to room temperature. The suspension was filtered, the solids were rinsed with ethanol (2×20 mL), and the combined filtrates were concentrated in-vacuo. The residue thus obtained was stirred in 2 N aqueous HCl (30 mL). The resulting solids were collected by filtration, rinsed with ice-cold water (2×20 mL), and air dried to yield 12.1 g of 5-Bromo-2-tert-butyl-pyrimidine-4-carboxylic acid as a beige powder. MS (ES+)=259, 261 (M+H)+.

1. additionWhen the addition
2. customthe heating mantle was removed
3. customto exceed 55° C
4. additionWhen this addition
5. temperatureto cool to room temperature
6. filtrationThe suspension was filtered
7. washthe solids were rinsed with ethanol (2×20 mL)
8. concentrationthe combined filtrates were concentrated in-vacuo
9. customThe residue thus obtained
10. filtrationThe resulting solids were collected by filtration
11. washrinsed with ice-cold water (2×20 mL), and air
12. customdried