Water → tert-Butyl 4-(4-amino-2-cyanophenyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Ammonium chloride (7.0 g) and iron powder (36.6 g) were added to a mixed solvent of water (180 ml) and ethanol (540 ml), and the mixture was heated to 65° C. Then, 5-nitro-2-(4-tert-butoxycarbonylpiperazin-1-yl)benzonitrile (62.1 g) was added in parts over 40 min and the mixture was stirred at a refluxing temperature for 1 h. The reaction mixture was ice-cooled and filtrated. The solvent was evaporated under reduced pressure. To the residue was added aqueous sodium hydroxide solution, and the mixture was extracted with toluene. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate, after which the solvent was evaporated under reduced pressure. Diisopropyl ether was added to the residue to allow crystallization. The crystals were recrystallized from a mixed solvent of ethyl acetate-n-hexane to give the title compound (50.7 g), melting point: 145° C.

Provenance & Evidence