反应详情

A mixture of 2,5-dichloronicotinic acid (Syn. Commun. 1989, 19, 553–9, 500 mg, 2.6 mmol), 3-chloro-5-hydroxypyridine (404 mg, 3.1 mmol), copper bronze (36 mg, 0.57 mmol), cuprous iodide (40 mg, 0.21 mmol) and potassium carbonate (792 mg, 5.7 mmol) in N,N-dimethylforamide (7 mL) was heated under reflux for 3 h. The reaction mixture was filtered through a pad of Celite® and the filtrate was concentrated. The residue was diluted with water (10 mL) and the mixture was acidified with 2 N hydrochloric acid (2 mL). Precipitateed solids were collected by filtration and dried under reduced presssure at 40° C. to afford 349 mg of the title compound: 1H-NMR (CDCl3) δ 8.37 (3H, br.s), 7.96 (2H, br.s), a peak of COOH was not observed; MS (ESI) m/z 285 (M+H)+.—

1. temperaturewas heated
2. temperatureunder reflux for 3 h
3. filtrationThe reaction mixture was filtered through a pad of Celite®
4. concentrationthe filtrate was concentrated
5. additionThe residue was diluted with water (10 mL)
6. filtrationPrecipitateed solids were collected by filtration
7. customdried
8. customat 40° C.