Water → 2-Pyridinecarboxylic acid, 3-[2-(3-chlorophenyl)ethyl]-

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Reaction Conditions

Reaction Steps

3-[2-(3-chlorophenyl)ethyl]-N-(1,1-dimethylethyl)-2-pyridine carboxamide (1.0 mole, 317g), sulfuric acid (325 mL) and water (300 mL) are refluxed at about 130° C. for aporoximately 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%.

Provenance & Evidence