Hydrochloric Acid → HCID 13504101, compound

Participants

Reaction Steps

A solution of 4-trifluoromethoxybromobenzene (6.3 g.) in dry tetrahydrofuran (40 cm3) was added dropwise to a stirred mixture of magnesium turnings (0.62 g.), dry tetrahydrofuran (10 cm3) and a crystal of iodine under a nitrogen atmosphere. The reaction commenced after about 3 cm3 of the solution had been added and the mixture was warmed gently for a few minutes. When the addition was complete the mixture was stirred for 2 hours after which a solution of methyl 2-(1H-pyrazol-1-yl)propionate (2.0 g) in dry tetrahydrofuran (5.0 cm3) was added dropwise and the mixture then stirred for a further 2 hours at the ambient temperature. Finally the mixture was warmed to 40° C. to complete the reaction. The mixture was poured into water, acidified with dilute hydrochloric acid and extracted with two portions of diethyl ether 2×50 cm3. The extracts were combined, washed with water (3×50 cm3), dried over anhydrous magnesium sulphate and concentrated by removal of the solvent by evaporation under reduced pressure. The residual oil was subjected to purification by repeated chromatographic separation on a silica gel column eluted with a mixture of petroleum ether (boiling range 60°-80° C., 4 parts by volume) and ethyl acetate (1 part by volume) to yield 1,1-bis(4-trifluoromethoxyphenyl)-2-(1H-pyrazol-1-yl) propanol (500 mg.) as a pale yellow oil.

Provenance & Evidence