4-Fluoro-3-nitrophenylboronic acid → tert-butyl 1-(4-fluoro-3-nitrophenyl)-3-isopropyl-1H-pyrazole-5-carboxylate

HRID 2042116Notes

Reaction equation

HRID 2042116 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5](B(O)O)=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12].[CH:14]([C:17]1[CH:21]=[C:20]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[NH:19][N:18]=1)([CH3:16])[CH3:15]>C(Cl)Cl.C([O-])(=O)C.[Cu+2].C([O-])(=O)C>[F:1][C:2]1[CH:7]=[CH:6][C:5]([N:19]2[C:20]([C:22]([O:24][C:25]([CH3:27])([CH3:26])[CH3:28])=[O:23])=[CH:21][C:17]([CH:14]([CH3:16])[CH3:15])=[N:18]2)=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12]

Participants

5

Reactant 2

HCID 249017654-Fluoro-3-nitrophenylboronic acid2×HCID 178439316HCID 178439316, compound

Product 1

HCID 67253215tert-butyl 1-(4-fluoro-3-nitrophenyl)-3-isopropyl-1H-pyrazole-5-carboxylateYield 44%

Reagents, catalysts & solvents 2

HCID 8895Cupric acetateCatalystHCID 6344DichloromethaneSolvent

Procedure

4-Fluoro-3-nitrophenylboronic acid (0.9 g, 4.9 mmol) was dissolved in CH2Cl2 (10 mL) and pyridine (1 mL) with MS (activated 4A) and dried for 6 hours. A mixture of 4-fluoro-3-nitrophenylboronic acid, tert-butyl 3-isopropyl-1H-pyrazole-5-carboxylate (1.0 g, 4.9 mmol), copper(II) acetate (0.88 g, 4.9 mmol) and molecular sieves (4A activated, powder) was stirred at RT for 7 days open to the air. The reaction mixture was filtered through a pad of Celite. The filtrate was concentrated in vacuo and purified by silica gel column chromatography (EtOAc/hexane) to obtain tert-butyl 1-(4-fluoro-3-nitrophenyl)-3-isopropyl-1H-pyrazole-5-carboxylate (0.74 g, 44% yield). MS (ESI) m/z: 350.3 (M+H+).

Workup

  1. dry with materialpyridine (1 mL) with MS (activated 4A) and dried for 6 hours
  2. filtrationThe reaction mixture was filtered through a pad of Celite
  3. concentrationThe filtrate was concentrated in vacuo
  4. custompurified by silica gel column chromatography (EtOAc/hexane)

Sources & evidence

ORD record
ord-2344ff43471a4034813bc494dce79939
Source dataset
uspto-grants-2013_11
Patent number
US08586565B2

Reaction notes

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