tert-Butyl piperazine-1-carboxylate → Tert-butyl 4-(4-cyano-2-methylphenyl)piperazine-1-carboxylate

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Reaction Steps

Part 4: To a nitrogen flushed flask containing PdCl2dppf (65.8 mg, 0.081 mmol), dppf (44.6 mg, 0.081 mmol) and 4-bromo-3-methylbenzonitrile (631 mg, 3.22 mmol) in THF (5 mL) at −78° C. was added tert-butyl 1-piperazinecarboxylate (500 mg, 2.68 mmol) as a solid. The resultant mixture was heated to 100° C. and vigorously stirred overnight under nitrogen. The reaction was quenched with water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried (MgSO4) and concentrated under reduced pressure. The residue was purified by flash chromatography (eluting with 0 to 30% ethyl acetate in hexane) to afford 4-(4-cyano-2-methyl-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (702 mg, 86.9%). MS (ESI): 302.0 (M+H+).

Provenance & Evidence