Diisopropylethylamine → (+/-) tert-butyl 2-methyl-4-(4-nitro-1-(2,2,2-trifluoroethyl)-1H-pyrazol-5-yl)piperazine-1-carboxylate

Participants

Reaction Steps

A solution of Intermediate 39, 5-bromo-4-nitro-1-(2,2,2-trifluoroethyl)-1H-pyrazole (550 mg, 2.01 mmol), (±) tert-butyl 2-methylpiperazine-1-carboxylate (403 mg, 2.01 mmol), DIPEA (2 mL) in EtOH (6 mL) was stirred at 130° C. for 2 hours in a microwave oven. The reaction mixture was concentrated under reduced pressure to give a residue. The residue was purified by silica gel chromatography using PE:EtOAc (1:1) as eluting solvents to afford tert-butyl (±)-2-methyl-4-(4-nitro-1-(2,2,2-trifluoroethyl)-1H-pyrazol-5-yl)piperazine-1-carboxylate as yellow solid (377 mg, 48%). MS (ESI) m/z: 394 [M+H+].

Provenance & Evidence