Phosphorus tribromide → 4-(bromomethyl)-1-[4-(trifluoromethoxy)phenyl]-1H-pyrazole

HRID 1496930Notes

Reaction equation

HRID 1496930 reaction equation
P(Br)(Br)[Br:2].[F:5][C:6]([F:22])([F:21])[O:7][C:8]1[CH:13]=[CH:12][C:11]([N:14]2[CH:18]=[C:17]([CH2:19]O)[CH:16]=[N:15]2)=[CH:10][CH:9]=1>CCOCC>[Br:2][CH2:19][C:17]1[CH:16]=[N:15][N:14]([C:11]2[CH:12]=[CH:13][C:8]([O:7][C:6]([F:22])([F:21])[F:5])=[CH:9][CH:10]=2)[CH:18]=1

Participants

4

Reactant 2

HCID 24614Phosphorus tribromideHCID 44818855{1-[4-(trifluoromethoxy)phenyl]-1H-pyrazol-4-yl}methanol

Product 1

HCID 448190334-(bromomethyl)-1-[4-(trifluoromethoxy)phenyl]-1H-pyrazoleYield 81.5%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

PBr3 (76 μL, 0.81 mmol) was added to a solution of alcohol 117 (0.210 g, 0.813 mmol) in ether (10 mL) at 0° C. The mixture was stirred at room temperature for 2 h, then cooled to 0° C., quenched with ice, and partitioned between Et2O and water. Column chromatography of the organic portion on silica gel (eluting with CH2Cl2) gave 4-(bromomethyl)-1-[4-(trifluoromethoxy)phenyl]-1H-pyrazole (118) (0.212 g, 81%) as a white solid: mp 50-51° C.; 1H NMR (CDCl3) δ 7.94 (d, J=0.5 Hz, 1H), 7.74 (s, 1H), 7.69 (d, J=9.1 Hz, 2H), 7.31 (d, J=9.1 Hz, 2H), 4.50 (s, 2H). APCI MS m/z 321, 323 [M+H]+.

Workup

  1. temperaturecooled to 0° C.
  2. customquenched with ice
  3. custompartitioned between Et2O and water

Sources & evidence

ORD record
ord-dd5ce8e2fa514db88ab00a8e641379a5
Source dataset
uspto-grants-2015_12
Patent number
US09198913B2

Reaction notes

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