Sodium Iodide → 3-(3-Fluoro-5-chloro-2-pyridyl)-5-(2.2.2-trifluoroethoxy)-1-methyl-[1H]-pyrazole

Participants

Reaction Conditions

Reaction Steps

3.0 g of 3-(3-fluoro-5-chloro-2-pyridyl)-5-hydroxy-1-methyl-[1H]-pyrazole (Example H14) are initially introduced into 30 ml of N-methylpyrrolidone (NMP) together with 3.64 g of potassium carbonate, and 3.49 g of 2,2,2-trifluoro-ethanol 4-methylbenzenesulfonate are added. 0.3 g of sodium iodide is then added and the mixture is stirred overnight at 80° C. It is then cooled to 22° C. and partitioned between dilute hydrochloric acid and diethyl ether. After extraction by shaking and separation of the phases, the ether phase is washed with brine, filtered and concentrated in vacuo together with twice the amount of silica gel. After application of the silica gel to a flash column, the column is eluted with n-hexane/ethyl acetate 2/1. 2.68 g of the desired title compound are obtained as a yellow solid of melting point 72-73° C.

Provenance & Evidence