Acetone → N-(1-methylethyl)-2-[4-(2-pyrimidinyl)-1-piperazinyl]ethylamine

To a solution of 2-[4-(2-pyrimidinyl)-1-piperazinyl]ethylamine (2.46 g, 0.012 mol) in methanol (45 mL) was added acetone (0.9 mL, 0.012 mol) and zinc chloride/sodium cyanoborohydride solution in dichloromethane (24 mL, containing 0.006 mol zinc chloride and 0.012 mol sodium cyanoborohydride) at room temperature. The resulting mixture was stirred at room temperature for 1 hour, and then an additional portion of the zinc chloride/cyanoborohydride solution (2 mL) was added. The mixture was then stirred at room temperature for 2 days. To the reaction mixture was added 1M aqueous sodium hydroxide solution (18 mL). The methanol was removed on a rotary evaporator, and the residue was partitioned between dichloromethane (100 mL) and brine solution (100 mL). The organic layer was dried over anhydrous magnesium sulfate and concentrated on a rotary evaporator. The desired intermediate, N-(1-methylethyl)-2-[4-(2-pyrimidinyl)-1-piperazinyl]ethylamine (TLC on silica gel using 30% methanol in ethyl acetate, Rf=0.31 ), was isolated as a colorless oil by cttromatography on 250 gm of silica gel using 30% methanol/ethyl acetate as the eluant (1.28 g, 50% yield).

1. stirringThe mixture was then stirred at room temperature for 2 days
2. customThe methanol was removed on a rotary evaporator
3. customthe residue was partitioned between dichloromethane (100 mL) and brine solution (100 mL)
4. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
5. concentrationconcentrated on a rotary evaporator

ORD record

ord-9e7d5a2d2e4141a287ba44cf4c7d3e5d

Source dataset

uspto-grants-1996_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05482940