Formaldehyde → (2R)-1-[3,5-bis(trifluoromethyl)benzoyl]-2-(3,4-dimethylbenzyl)-4-(4-hydroxy-2-butynyl)piperazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 37% aqueous formaldehyde (0.21 g), (2R)-1-[3,5-bis(trifluoromethyl)benzoyl]-2-(3,4-dimethylbenzyl)piperazine (0.75.g), propargyl alcohol (0.11 ml), copper(II) sulfate pentahydrate (1.3 mg) and potassium iodide (2.8 mg) in 1,4-dioxane was stirred at 100° C. for 2 hours. After being cooled to room temperature, the mixture was made basic with aqueous saturated sodium hydrogen carbonate solution. The resulting mixture was filtered and the filtrate was extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel using a mixed solvent of n-hexane and ethyl acetate (4:1). The fractions containing the objective compound was collected and evaporated under reduced pressure to give (2R)-1-[3,5-bis(trifluoromethyl)benzoyl]-2-(3,4-dimethylbenzyl)-4-(4-hydroxy-2-butynyl)piperazine (0.78 g) as a syrup.

Provenance & Evidence