反应详情

温度

50 °C

2-Amino-N-(5-chloro-2-pyridyl)-3-hydroxybenzamide (3.06 g) and 1.80 g of N-chlorosuccinimide were dissolved in 60 ml of N,N-dimethylformamide, the solution was stirred at 50° C. for 8 hours and at room temperature for 4 hours and the insoluble matter was filtered off. The solvent was evaporated in vacuo, to the resulting residue was added a 1N aqueous solution of sodium hydroxide and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, the solvent was evaporated in vacuo and the resulting residue was purified by means of a silica gel column chromatography. Ethanol was added to the crudely purified product and the resulting precipitate was collected by filtration and dried in vacuo to give 767 mg of 2-amino-5-chloro-N-(5-chloro-2-pyridyl)-3-hydroxybenzamide. The mother liquor was concentrated, then ethyl acetate-isopropyl ether was added thereto and the resulting precipitate was collected by filtration and dried in vacuo to give more 942 mg of the above-mentioned compound.

1. filtrationthe insoluble matter was filtered off
2. customThe solvent was evaporated in vacuo, to the resulting residue
3. additionwas added a 1N aqueous solution of sodium hydroxide
4. extractionthe mixture was extracted with ethyl acetate
5. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
6. customthe solvent was evaporated in vacuo
7. customthe resulting residue was purified by means of a silica gel column chromatography
8. additionEthanol was added to the crudely purified product
9. filtrationthe resulting precipitate was collected by filtration
10. customdried in vacuo