反应详情

A solution of palladium acetate (224.5 mg, 1.00 mmol) and triphenylphosphine (1.05 g, 4.00 mmol) in toluene (1000 mL) was stirred at room temperature for 15 minutes. Phenylboronic acid (114 g, 935 mmol), 2-chloro-3-aminopyridine (100 g, 778 mmol), benzaldehyde (83.4 g, 786 mmol), and toluene (500 mL) were then added followed by a solution of sodium carbonate (200 g, 1.89 mol) in water (1500 mL). The mixture was heated to reflux for 18 hours, cooled to room temperature, and the layers were separated. The organic layer was washed with water (500 mL) and 2.5M aqueous hydrochloric acid was added (630 mL). The aqueous layer was separated and washed with toluene (300 mL). The pH was adjusted to 12—13 using 50% aqueous sodium hydroxide and the mixture was extracted with methyl-tert-butyl ether (500 mL). The organic layer was concentrated and the product was crystallized from diisopropyl ether to afford 2-phenyl-3-aminopyridine (128 g, 97% yield). M. p.=67-68° C. 1H NMR (300 MHz, CDCl3) δ3.88 (bs, 2), 7.02-7.11 (m, 2). 7.28-7.53 (m, 3), 7.67-7.71 (m, 2), 8.,13-8.16 (m, 1). 13C NMR (100 MHz, CDCl3) δ122.57, 122.96, 128.14, 128.38, 128.72, 138.54, 139.86, 139.93, 144.93.

1. temperatureThe mixture was heated
2. temperatureto reflux for 18 hours
3. customthe layers were separated
4. washThe organic layer was washed with water (500 mL) and 2.5M aqueous hydrochloric acid
5. additionwas added (630 mL)
6. customThe aqueous layer was separated
7. washwashed with toluene (300 mL)
8. extractionthe mixture was extracted with methyl-tert-butyl ether (500 mL)
9. concentrationThe organic layer was concentrated
10. customthe product was crystallized from diisopropyl ether