Dimethylformamide → 1H-Pyrazole-4-carboxamide, 5-cyano-N-methyl-1-phenyl-

Participants

Reaction Conditions

Reaction Steps

A 50 gallon reactor was charged with 16.6 kg (66.3 mol) of 5-chloro-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester and 40 l. of DMF. To the stirred solution was added 6.5 kg (132.6 mol) of sodium cyanide and the resulting reaction mixture was heated at 85° C. for 5 hours. The mixture was allowed to stir overnight at room temperature. A thin layer chromatograph in methylene chloride of a sample of the reaction mixture indicated the presence of a small amount of starting material. the reaction mixture was heated to 100° C. for 2 hours and cooled. The mixture was charged with 18 kg (232 mol) of 40% aqueous methylamine. The mixture was stirred at room temperature overnight and 40 l. of ice water was added. The mixture was stirred at about 10° C. for one hour using a cooling jacket and the precipitated solid was collected by filtration. The solid was washed with water several times and dried to provide 12.4 kg of 5-cyano-1-phenyl-N-methyl-1H-pyrazole-4-carboxamide. Yield 82.7%. Purity of this material by HPLC was 98.14%. mp=203°-205° C.

Provenance & Evidence