Diethyl Ether → 5-Amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-(2-fluorophenyl)pyrazole

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Reaction Steps

To a rapidly stirred solution of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-iodopyrazole (0.335 g) in toluene (2 ml) containing tetrakis(triphenylphosphine)palladium(0) (0.03 g) was added saturated aqueous sodium hydrogen carbonate solution (1 ml) and a solution of 2-fluorophenylboronic acid (0.210 g) in ethanol (1 ml). The mixture was heated under reflux for 5.5 hours, cooled and then poured into ether (25 ml) and water (25 ml). The organic layer was separated, washed with water (25 ml), brine (25 ml) and then dried (Na2SO4) and evaporated. The residue was purified by column chromatography on silica gel (40 g) eluted with dichloromethane. Combination and evaporation of suitable fractions gave the title compound as a white crystalline solid, m.p. 197° C.

Provenance & Evidence