反应详情

温度

-20 °C

The solution of 24.9 g of 5-benzylideneaminopyridine-2-carboxylic acid methyl ester in 70 ml of hot dimethylformamide is added all at once to the solution of 7.0 g of sodium borohydride in 300 ml of methanol while stirring at -20° C. The temperature of the reaction mixture raises spontaneously to 20° and is lowered to 0° by cooling. After 2 hours the mixture is warmed to room temperature for 15 minutes to ensure complete reaction. Approximately 1/2 of the methanol is distilled off, the concentrate is cooled to 0° and 3 ml of acetic acid and the solution of 12 ml of 12 N hydrochloric acid in 100 ml ice water is added. A precipitate begins to separate and 200 ml more ice water are added. After 30 minutes the precipitate is collected and washed well with water and recrystallized from acetonitrile, to yield the 5-benzylaminopyridine-2-carboxylic acid methyl ester, melting at 104°-107°.

1. temperatureThe temperature of the reaction mixture raises spontaneously to 20°
2. customis lowered to 0°
3. temperatureby cooling
4. temperatureAfter 2 hours the mixture is warmed to room temperature for 15 minutes
5. customreaction
6. distillationApproximately 1/2 of the methanol is distilled off
7. temperaturethe concentrate is cooled to 0°
8. addition3 ml of acetic acid and the solution of 12 ml of 12 N hydrochloric acid in 100 ml ice water is added
9. customto separate
10. addition200 ml more ice water are added
11. customAfter 30 minutes the precipitate is collected
12. washwashed well with water
13. customrecrystallized from acetonitrile