反应详情

Slurry crude 2-bromo-5-(2-bromo-acetyl)-pyridine (11.5 g, ca. 48%), cyclopropylmethyl-thiourea (2.2 g, 16.9 mmol) and sodium bicarbonate (1.7 g, 20 mmol) in ethanol (100 mL) at room temperature. Stir the mixture at reflux for 1 h under a nitrogen atmosphere. Turn off heat and stir the mixture for 16 h at room temperature. Filter the slurry, then wash the solids with ethanol (50 mL), water (2×50 mL) and hexane (excess). Dry the solid in a vacuum oven for 20 h at 50° C. to obtain the desired intermediate as a tan solid (3.2 g, 61% over 2 steps). MS (ES+) m/z: 312 (M+2)+.

1. customat room temperature
2. temperatureat reflux for 1 h under a nitrogen atmosphere
3. temperatureheat
4. stirringstir the mixture for 16 h at room temperature
5. filtrationFilter the slurry
6. washwash the solids with ethanol (50 mL), water (2×50 mL) and hexane (excess)
7. customDry the solid in a vacuum oven for 20 h at 50° C.