反应详情

To a N2 covered suspension of 3.0 g (21.6 mmol) of 2-amino-5-nitropyridine in 12 ml of CH2C12 was added 9.9 ml (71.2 mmol) of triethylamine followed by 0.13 g (1.1 mmol) of 4-dimethylaminopyridine. The mixture was cooled in an ice bath and there was added 5.06 ml (71.2 mmol) of acetyl chloride dropwise over 18 minutes. The ice bath was removed and after stirring at room temperature for 18 hours, the reaction mixture was diluted with CH2Cl2 and washed once with 20 ml of 1M aqueous K2CO3. The aqueous layer was separated and extracted twice with CH2Cl2. The combined organic fractions were dried over MgSO4 and concentrated in vacuo. The residue was chromatographed over silica gel (20% EtOAc: hexane) and recrystallized from CH3CN to yield 0.653 g, m.p. 196.5°-198° C. (16.7%), 0.157 g, m.p. 183°-193° C. (4.0%) and 0.057 g, m.p. 191°-196° C (1.5%) of the titled product.

1. temperatureThe mixture was cooled in an ice bath
2. customThe ice bath was removed
3. additionthe reaction mixture was diluted with CH2Cl2
4. washwashed once with 20 ml of 1M aqueous K2CO3
5. customThe aqueous layer was separated
6. extractionextracted twice with CH2Cl2
7. dry with materialThe combined organic fractions were dried over MgSO4
8. concentrationconcentrated in vacuo
9. customThe residue was chromatographed over silica gel (20% EtOAc: hexane)
10. customrecrystallized from CH3CN