反应详情

温度

55 °C

Sodium (356 mg, 15.5 mmol) was carefully added to ethanol (5.9 mL) to prepare sodium ethoxide solution in ethanol. The above freshly prepared ethanol solution (3.5 mL) was added to a stirred suspension of propionimidamide hydrochloride (1.05 g, 9.69 mmol). The mixture was warmed to 55° C., then the heating bath was removed and a solution of mucobromic acid (1 g, 3.87 mmol) in ethanol was added dropwise at a rate which maintained a constant temperature, followed by a further sodium ethoxide solution (2 mL). After cooling, the mixture was filtered and evaporated to a residue which was shaken vigorously with hydrochloric acid (2 M×2.4 mL). The brown precipitate was filtered off and washed with cold water, then freeze-dried to give 5-Bromo-2-ethylpyrimidine-4-carboxylic acid (330 mg, 37%) as a yellow solid. LCMS: 231 [M+1]+, 1H NMR (400 MHz, DMSO-d6): δ 1.25 (t, J=7.6 Hz, 3H), 2.88 (q, J=7.6 Hz, 2H), 9.05 (s, 1H).

1. customthe heating bath was removed
2. temperaturemaintained a constant temperature
3. temperatureAfter cooling
4. filtrationthe mixture was filtered
5. customevaporated to a residue which
6. filtrationThe brown precipitate was filtered off
7. washwashed with cold water
8. customfreeze-dried