反应详情

温度

35 °C

3-[2-(3-chlorophenyl)ethyl]-N-(1,1-dimethylethyl)-2-pyridine carboxamide (1.0 mole, 317 g), sulfuric acid (325 mL) and water (300 mL) are refluxed at about 130° C. for approximately 2 hours. Completeness of the reaction is determined by thin layer chromatography. The reaction mixture is cooled to about 35° C. and added to ice (2 kg). The mixture is then brought to about pH 11 with 50% sodium hydroxide. Additional ice (1 kg) is added, followed by ethyl acetate (1 liter) and hexane (525 mL). The mixture is acidified to about pH 4 with sulfuric acid and stirred for about 1 hour. Crude product is isolated by filtration, washed with water and hexane and optionally dried at about 50° C. Then the crude product is dissolved in ethyl acetate by refluxing at about 75° C. After treating the solution with decolorizing carbon (5 g), the filtrate is concentrated and cooled to about 15° C. Purified product is isolated by filtration, washed with hexane: ethyl acetate (3:1) and dried at about 50° C. A second crop may be obtained by concentrating the mother liquor and recrystallizing from ethyl acetate as described above. The yield of product is shown to be 60%.

1. customCrude product is isolated by filtration
2. washwashed with water and hexane
3. customoptionally dried at about 50° C
4. dissolutionThen the crude product is dissolved in ethyl acetate
5. temperatureby refluxing at about 75° C
6. additionAfter treating the solution with decolorizing carbon (5 g)
7. concentrationthe filtrate is concentrated
8. temperaturecooled to about 15° C
9. customPurified product is isolated by filtration
10. washwashed with hexane: ethyl acetate (3:1)
11. customdried at about 50° C
12. customA second crop may be obtained
13. concentrationby concentrating the mother liquor
14. customrecrystallizing from ethyl acetate