3-(CHLORO-DIFLUORO-METHYL)-5-METHYL-1H-PYRAZOLE synthesis

Yield:321998-14-5 73%

Reaction Conditions:

with acetic acid;hydrazine at 20; for 2 h;regioselective reaction;

Steps:

3.7. General procedure for the synthesis of compounds 20a, 20c, 20e-f

General procedure: A solution of 1.0 equiv of the chlorodifluorodiketone or of (Z)-1-chloro-4-ethoxy-1,1-difluorbut-3-en-2-one and of 1.0 equiv of the hydrazine in acetic acid (8 mL per 1 mmol of starting material) was stirred for 2 h at room temperature. The solvent was evaporated, and the crude product was purified by column chromatography to give the pure product.

References:

Iaroshenko, Viktor O.;Specowius, Verena;Vlach, Katharina;Vilches-Herrera, Marcelo;Ostrovskyi, Dmytro;Mkrtchyan, Satenik;Villinger, Alexander;Langer, Peter [Tetrahedron,2011,vol. 67,# 31,p. 5663 - 5677] Location in patent:experimental part