Diethyl Ether → HCID 22120922, compound

Participants

Reaction Steps

To a rapidly stirred solution of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-iodopyrazole (0.447 g) in toluene (2 ml) containing tetrakis(triphenylphosphine)palladium(0) (0.02 g) was added saturated aqueous sodium hydrogen carbonate solution (1 ml) and a solution of thiophene-3-boronic acid (0.256 g) in ethanol (1 ml). The mixture was heated under reflux for 3 hours, then left at room temperature overnight. Saturated aqueous sodium hydrogen carbonate solution (0.5 ml) and tetrakis(triphenylphosphine)palladium(0) (0.01 g) were added and the mixture heated under reflux for 3 hours. Thiophene-3-boronic acid (0.178 g) and tetrakis(triphenylphosphine)palladium(0) (0.02 g) were added and heating under reflux continued for 16 hours. The cooled reaction mixture was then poured into ether (25 ml) and water (25 ml). The layers were separated and the aqueous phase extracted with a second portion of ether (25 ml). The combined organic layers were washed with water (2×25 ml), brine (25 ml) and then dried (MgSO4) and evaporated. The residue was purified by column chromatography on silica gel (50 g) eluted with dichloromethane. Combination and evaporation of suitable fractions gave the title compound as a white crystalline solid, m.p. 210-2° C.

Provenance & Evidence