Phosphorus tribromide → Ethyl 5-bromo-4-(bromomethyl)-1-phenyl-1H-pyrazole-3-carboxylate

HRID 1521849Notes

Reaction equation

HRID 1521849 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:10]([CH2:11]O)=[C:9]([Br:13])[N:8]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[N:7]=1)=[O:5])[CH3:2].P(Br)(Br)[Br:21]>CCOCC>[Br:13][C:9]1[N:8]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[N:7]=[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[C:10]=1[CH2:11][Br:21]

Participants

4

Reactant 2

HCID 24614Phosphorus tribromideHCID 66579973Ethyl 5-bromo-4-(hydroxymethyl)-1-phenyl-1H-pyrazole-3-carboxlate

Product 1

HCID 66578936Ethyl 5-bromo-4-(bromomethyl)-1-phenyl-1H-pyrazole-3-carboxylateYield 60.3%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a solution of ethyl-5-bromo-4-(hydroxymethyl)-1-phenyl-1H-pyrazole-3-carboxylate (2.91 g, 8.98 mmol, 1 eq) in Et2O cooled at −10° C. is added phosphorus tribromide (1.02 mL, 10.77 mmol, 1.2 eq) and the reaction mixture is stirred at Rt for 1 h. The reaction mixture is poured over ice and extracted with MTBE. The organic layer is washed with brine, dried over Na2SO4 and concentrated to afford 2.1 g (60%) of the title compound. 1H NMR (DMSO-d6, 400 MHz): δ 7.65-7.57 (m, 5H), 4.77 (s, 2H), 4.35 (q, J=6.0 Hz, 2H), 1.32 (t, J=6.6 Hz, 3H). HPLC (max plot) 83.30%; Rt 5.33 min.

Workup

  1. additionThe reaction mixture is poured over ice
  2. extractionextracted with MTBE
  3. washThe organic layer is washed with brine
  4. dry with materialdried over Na2SO4
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-3b4592aced8d41e0a02d4a009f7de025
Source dataset
uspto-grants-2015_07
Patent number
US09073940B2

Reaction notes

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