Phosphorus tribromide → 5-(bromomethyl)-1-methyl-3-[4-(trifluoromethoxy)phenyl]-1H-pyrazole

HRID 1496905Notes

Reaction equation

HRID 1496905 reaction equation
P(Br)(Br)[Br:2].[CH3:5][N:6]1[C:10]([CH2:11]O)=[CH:9][C:8]([C:13]2[CH:18]=[CH:17][C:16]([O:19][C:20]([F:23])([F:22])[F:21])=[CH:15][CH:14]=2)=[N:7]1>CCOCC>[Br:2][CH2:11][C:10]1[N:6]([CH3:5])[N:7]=[C:8]([C:13]2[CH:18]=[CH:17][C:16]([O:19][C:20]([F:23])([F:22])[F:21])=[CH:15][CH:14]=2)[CH:9]=1

Participants

4

Reactant 2

HCID 24614Phosphorus tribromideHCID 44818672{1-methyl-3-[4-(trifluoromethoxy)phenyl]-1H-pyrazol-5-yl}methanol

Product 1

HCID 448186755-(bromomethyl)-1-methyl-3-[4-(trifluoromethoxy)phenyl]-1H-pyrazoleYield 85%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

PBr3 (0.15 mL, 1.60 mmol) was added to a solution of alcohol 72 (0.205 g, 0.75 mmol) in Et2O (10 mL) at 0° C. The mixture was stirred at room temperature for 16 h, cooled to 0° C., quenched with ice and diluted with Et2O (100 mL). Chromatography of the organic portion on silica gel (eluting with CH2Cl2) gave 5-(bromomethyl)-1-methyl-3-[4-(trifluoromethoxy)phenyl]-1H-pyrazole (73) (0.212 g, 85%) as a white solid: mp 70-71° C.; 1H NMR (CDCl3) δ 7.76 (d, J=8.9 Hz, 2H), 7.22 (d, J=8.9 Hz, 2H), 6.55 (s, 1H), 4.50 (s, 2H), 3.94 (s, 3H). APCI MS m/z 335, 337 [M+H]+.

Workup

  1. temperaturecooled to 0° C.
  2. customquenched with ice
  3. additiondiluted with Et2O (100 mL)

Sources & evidence

ORD record
ord-ea97fe62a780497081dcd615de1b81ea
Source dataset
uspto-grants-2015_12
Patent number
US09198913B2

Reaction notes

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