Sodium Bicarbonate → 4-bromo-3-methoxy-1-methyl-1H-pyrazole

HRID 2095686Notes

Reaction equation

HRID 2095686 reaction equation
[CH3:1][O:2][C:3]1[CH:7]=[CH:6][N:5]([CH3:8])[N:4]=1.[Br-:9].[Br-].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.C([O-])(O)=O.[Na+]>CO.O>[Br:9][C:7]1[C:3]([O:2][CH3:1])=[N:4][N:5]([CH3:8])[CH:6]=1

Participants

6

Reactant 3

HCID 516892Sodium BicarbonateHCID 186223703-Methoxy-1-methyl-1H-pyrazoleHCID 21124087Pyridiniumtribromide

Product 1

HCID 670039094-bromo-3-methoxy-1-methyl-1H-pyrazole

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 3-methoxy-1-methyl-1H-pyrazole (0.500 g, 4.46 mmol) in MeOH (50.0 mL) was cooled to 0° C. and charged with pyridinium tribromide (1.43 g, 4.46 mmol) in portions. The solution was stirred for 1 h at 0° C. then for an additional 16 h at rt. The reaction mixture was charged with sat. NaHCO3 (2.5 mL) and diluted with H2O and extracted with CHCl3 (3×). The combined organic fractions were dried over Na2SO4, filtered and concentrated in vacuo resulting in the title compound as a red oil. This material was used in the next step without further purification. 1H NMR (400 MHz, CD3OD): δ=3.66 (s, 3H), 4.07 (s, 3H), 7.30 (s, 1H). MS (ES+): m/z 190.98, 192.99 (49.5/50.5) [MH+]. HPLC: tR=2.29 min (polar—5 min, ZQ3).

Workup

  1. waitfor an additional 16 h at rt
  2. extractionextracted with CHCl3 (3×)
  3. dry with materialThe combined organic fractions were dried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-dad150b2e7b147419b31436ff62ae93c
Source dataset
uspto-grants-2013_05
Patent number
US08445510B2

Reaction notes

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