1H-Pyrazole-3-carbonitrile

33064-36-7

36650-74-5

The general method for synthesizing 3-carbonitrile pyrazoles from pyrazole-3-carboxamide is as follows: after completion of the preparation of the amide intermediate (Example A), the state of the reaction vessel is determined according to the boiling point of the amide intermediate in relation to the reaction temperature TB: if the boiling point of the amide intermediate at atmospheric pressure is equal to or lower than TB, the reaction vessel is closed; if the boiling point is higher than TB, the reaction vessel is kept open. Subsequently, stirring is continued at a rate of 600 rpm and the reaction temperature is adjusted to TB and maintained at this temperature for TD hours until the reaction is nearly complete. Upon completion of the reaction, the reaction vessel was sealed and connected to a vacuum pump, the vacuum in the reaction vessel was adjusted to 20-50 mbar (depending on the nature of the nitrile product) and the distillate was collected as the nitrile product. The yield of the product was calculated and samples were taken for NMR spectroscopy and elemental analysis to characterize the resulting nitrile product. The specific reaction conditions and characterization results are detailed in the following Tables A-7, A-8, A-9, A-10 and A-11. The characterization results showed that the resulting nitrile product was of very high purity (>99%). In some embodiments of the preparation of the nitrile product, 10 g of phosphorus pentoxide was optionally added as a catalyst at the beginning of the reaction.