1-(5-Trifluoromethyl-pyridin-2-yl)-piperazine → (3R)-1-Isopropyl-3-({4-[5-(trifluoromethyl)pyridin-2-yl]piperazin-1-yl}carbonyl)piperazine

Participants

Reaction Steps

1-[5-(Trifluoromethyl)pyridin-2-yl]piperazine (170 mg) and (2R)-1-(tert-butoxycarbonyl)-4-isopropylpiperazine-2-carboxylic acid (200 mg) were dissolved in dry THF (10 ml) followed by addition of N′N-di-isopropylethylamine (0.15 ml) and O-(7-Azabenzotriazol-1-yl)-N,N,N′,N′-TetramethylUronium Hexafluorophosphate (307 mg) and the reaction was stirred for 4 hours. The solvent was evaporated under reduced pressure, redissolved in DCM (50 ml) and washed with saturated aqueous NaHCO3 (20 ml). The organic layer was separated on a phase separation cartridge and evaporated. Purification by chromatography (3-10% MeOH:DCM) afforded the crude product (231 mg) as a foam which was then dissolved in TFA/DCM (1:1, 10 ml) and stirred for 30 minutes. The solvents were removed under reduced pressure, the residue taken up in 1M aqueous NaOH (30 ml) and extracted with DCM (2×30 ml). The organic layer was separated on a phase separation cartridge and evaporated. Purification by chromatography (5-25% MeOH:DCM) afforded the title compound (100 mg) as a white foam.

Provenance & Evidence