反应详情

(R)-(2,2-dimethyl-1,3-dioxolan-4-yl)methanol 54 (1.8 mL, 14.9 mmol) was added to a room temperature suspension of NaH (392 mg, 16.3 mmol) in THF (30 mL). The reaction mixture was stirred at room temperature for 30 min and 2-bromo-nicotinic acid 53 (1 g, 4.95 mmol) was added. The reaction mixture was heated at reflux for 12 h. After cooling to room temperature, the pH was adjusted to 3 by the addition of 3 N HCl. The mixture was poured into brine and extracted with EtOAc. The combined organics were dried and concentrated. The crude product was recrystallized from pentane/EtOAc to give 55 (1.2 g, 92% yield). The acetonide protecting group could be removed after coupling with the appropriate aniline by treatment with EtOH/3 N HCl (4:1) at reflux for 12 h.

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 12 h
3. temperatureAfter cooling to room temperature
4. extractionextracted with EtOAc
5. customThe combined organics were dried
6. concentrationconcentrated
7. customThe crude product was recrystallized from pentane/EtOAc