Acetic Acid → tert-Butyl 4-cyclopropylpiperazine-1-carboxylate

Participants

Reaction Steps

Piperazine-1-carboxylic acid tert-butyl ester (1.87 g), [(1-ethoxycyclopropyl)oxy]trimethylsilane (8.05 mL), and acetic acid (5.72 mL) were dissolved in methanol (60 mL). To the resultant solution, sodium cyanoborohydride (1.89 g) was added at room temperature, followed by stirring for 5 days. Diethyl ether was added to the residue obtained by removal through evaporation of the reaction solvent under reduced pressure, and insoluble matter was filtered off. The filtrate was partitioned by addition of aqueous 1N sodium hydroxide thereto. The organic layer was washed with saturated brine, and then dried over magnesium sulfate anhydrate, followed by filtration. The solvent was evaporated under reduced pressure. The residue was purified through silica gel column chromatography (hexane-ethyl acetate), to thereby give the title compound as a solid (1.62 g, 71%).

Provenance & Evidence