反应详情

24 ml (0.48 mol) of hydrazine hydrate are added dropwise to a solution of 92 g (0.4 mol) of 3-benzylamino-3-methylsulfanyl-2-cyano-acrylonitrile in 400 ml of methanol, the temperature rising to 40° C. The reaction mixture is slowly heated to boiling (e evolution of MeSH!), boiled for 2 hours, cooled to RT and concentrated by evaporation to a residual volume of ≈200 ml. Dilution with diethyl ether, filtration and washing with diethyl ether yield 5-amino-3-benzylamino-1H-pyrazole-4-carbonitrile [Spectrochimica Acta, 47A, 1635 (1991)]; m.p. 150-152° C.; TLC: Rf=0.41 (ethyl acetate).

1. customrising to 40° C
2. temperatureThe reaction mixture is slowly heated
3. concentrationconcentrated by evaporation to a residual volume of ≈200 ml
4. filtrationDilution with diethyl ether, filtration
5. washwashing with diethyl ether