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

HRID 1915895Notes

Reaction equation

HRID 1915895 reaction equation
Br[C:2]1[N:6]([CH2:7][C:8]([F:11])([F:10])[F:9])[N:5]=[CH:4][C:3]=1[N+:12]([O-:14])=[O:13].[CH3:15][CH:16]1[CH2:21][NH:20][CH2:19][CH2:18][N:17]1[C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23].CCN(C(C)C)C(C)C>CCO>[CH3:15][CH:16]1[CH2:21][N:20]([C:2]2[N:6]([CH2:7][C:8]([F:11])([F:10])[F:9])[N:5]=[CH:4][C:3]=2[N+:12]([O-:14])=[O:13])[CH2:19][CH2:18][N:17]1[C:22]([O:24][C:25]([CH3:26])([CH3:28])[CH3:27])=[O:23]

Participants

5

Reactant 3

HCID 81531DiisopropylethylamineHCID 15087784tert-Butyl 2-methylpiperazine-1-carboxylateHCID 569733215-bromo-4-nitro-1-(2,2,2-trifluoroethyl)-1H-pyrazole

Product 1

HCID 86680103(+/-) tert-butyl 2-methyl-4-(4-nitro-1-(2,2,2-trifluoroethyl)-1H-pyrazol-5-yl)piperazine-1-carboxylateYield 48%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

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+].

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. customto give a residue
  3. customThe residue was purified by silica gel chromatography
  4. washEtOAc (1:1) as eluting solvents

Sources & evidence

ORD record
ord-94417fb8ee8a449f95dd6b396bdc21e4
Source dataset
uspto-grants-2013_12
Patent number
US08614206B2

Reaction notes

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