Propargyl alcohol → 3-(3-Fluoro-5chloro-6-(1-hydroxy-2-propyn-3-yl)-2-pyridyl)4-chloro-5-difluoromethoxy-1-methyl-[1H]-pyrazole

Participants

Reaction Conditions

Reaction Steps

2.0 of 3-(3-fluoro-5,6-dichloro-2-pyridyl)-4-chloro-5difluoromethoxy-1-methyl-[1H]-pyrazole (Example H21) are initially introduced into 15 ml of triethylamine, and 0.37 ml of propargyl alcohol is added. The mixture is then evacuated and gassed with argon 3 times under a partial water pump vacuum. Thereafter, 0.03 g of copper(I) iodide and 0.12 g of bis-triphenylphosphine-palladium dichloride (PdCl2(PPH3)2) are added and the mixture is stirred overnight at 67° C. under argon. The following day, after cooling to 22° C., 0.20 ml of propargyl alcohol, 0.03 g of copper(l) iodide and 0.12 g of PdCl2(PPH3)2 are added. The mixture is then stirred at 67° C. for 6 hours. After cooling to 22° C., ethyl acetate is added and the mixture is washed successively with dilute hydrochloric acid, water and brine. After drying over sodium sulfate, filtration and concentration in vacuo, the residue is purified over a silica gel flash column (eluting agent: n-hexane/ethyl acetate 1/1). 0.97 g of the desired title compound is obtained as a yellow oil which gradually crystallizes; melting point 92-94° C.

Provenance & Evidence