反应详情

2-Nitro-4-(trifluoromethyl)benzoic acid (3.0 g) is suspended in chloroform (25 ml), and thereto are added oxalyl chloride (1.67 ml) and N,N-dimethylformamide (2 drops) followed by stirring at room temperature for 3 hours. The reaction solution is concentrated under reduced pressure, and to the residue is poured chloroform (20 ml) to obtain a suspension. Chloroform (30 ml) is added to 5-chloro-2-aminopyridine (1.56 g) and pyridine (1.55 ml), and the solution is ice-cooled. To the solution is added dropwise the suspension prepared above. The reaction solution is stirred at room temperature for 8 hours and concentrated under reduced pressure. The residue is diluted with ethyl acetate, washed successively with 10% aqueous potassium hydrogen sulfate solution, saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over magnesium sulfate, and evaporated to remove the solvent under reduced pressure. The resulting residue is suspended into n-hexane, filtered and dried to give N-(5-chloropyridin-2-yl)-2-nitro-4-(trifluoromethyl)-benzamide (4.73 g). APCI-MS M/Z: 346/348[M+H]+

1. concentrationThe reaction solution is concentrated under reduced pressure
2. additionto the residue is poured chloroform (20 ml)
3. customto obtain a suspension
4. temperaturecooled
5. additionTo the solution is added dropwise the suspension
6. customprepared above
7. stirringThe reaction solution is stirred at room temperature for 8 hours
8. concentrationconcentrated under reduced pressure
9. additionThe residue is diluted with ethyl acetate
10. washwashed successively with 10% aqueous potassium hydrogen sulfate solution, saturated aqueous sodium hydrogen carbonate solution and saturated brine
11. dry with materialdried over magnesium sulfate
12. customevaporated
13. customto remove the solvent under reduced pressure
14. filtrationfiltered
15. customdried