反应详情

温度

80 °C

5.2 g of 2,3-diaminopyridine in 209 g of polyphosphoric acid are heated at 120° C. for 0.5 h. The solution is cooled to 80° C. and 4.6 ml of 2-chloropropionitrile are added. Thereafter, the reaction mixture is heated to 180° C. for 2.5 h. After cooling, the polyphosphoric acid is hydrolyzed with water, the mixture is filtered using charcoal and celite and the pH value of the filtrate is adjusted to pH 4 using 9 M aqueous sodium hydroxide solution. The mixture is extracted twice each with 250 ml of ethyl acetate, the combined organic phases are dried using sodium sulfate, concentrated and lyophilized from ethanol/water to give 3.56 g of the title compound as a light brown, amorpheous solid. M.p. 132° C. TLC: Rf=0.60 (dichloromethane/methanol 8:1).

1. temperatureThereafter, the reaction mixture is heated to 180° C. for 2.5 h
2. temperatureAfter cooling
3. filtrationthe mixture is filtered
4. extractionThe mixture is extracted twice each with 250 ml of ethyl acetate
5. customthe combined organic phases are dried
6. concentrationconcentrated