Methanol → 4-[4-(1-Methoxy-1,1'-bicyclohexan-4-yl)piperazinyl]benzoic acid ethyl ester

Participants

Reaction Steps

To an ice cooled solution of ethyl 4-(piperazin-1-yl)benzoate (1.23 g) and 1-methoxy-1,1′-bicyclohexane-4-one (916 mg) in a mixed solvent of methanol (20 ml), tetrahydrofuran (15 ml) and acetic acid (0.74 ml) was added sodium cyanoborohydride (301 mg) in a stream of nitrogen. The mixture was stirred at this temperature for 1.5 hours and at room temperature for 7.5 hours. The reaction mixture was quenched with saturated aqueous sodium hydrogen carbonate solution. Dichloromethane was added to the solution. The organic layer was taken, washed with sodium hydrogen carbonate solution and dried over magnesium sulfate. The magnesium sulfate was filtered off, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography (3:1 hexane-methanol elution) to give 4-[4-(1-methoxy-1,1′-bicyclohexan-4-yl)piperazinyl]benzoic acid ethyl ester (801 mg).

Provenance & Evidence