3,5-Dimethylpyrazole → 1-[(4-Methoxyphenyl)methyl]-3,5-dimethyl-1H-pyrazole

HRID 220468Notes

Reaction equation

HRID 220468 reaction equation
[CH3:1][C:2]1[CH:6]=[C:5]([CH3:7])[NH:4][N:3]=1.[H-].[Na+].[CH3:10][O:11][C:12]1[CH:19]=[CH:18][C:15]([CH2:16]Cl)=[CH:14][CH:13]=1>CN(C)C=O.[Cl-].[NH4+]>[CH3:10][O:11][C:12]1[CH:19]=[CH:18][C:15]([CH2:16][N:3]2[C:2]([CH3:1])=[CH:6][C:5]([CH3:7])=[N:4]2)=[CH:14][CH:13]=1

Participants

6

Reactant 3

HCID 62103,5-DimethylpyrazoleHCID 24758Sodium hydrideHCID 699934-Methyloxybenzyl chloride

Product 1

HCID 233777481-[(4-Methoxyphenyl)methyl]-3,5-dimethyl-1H-pyrazoleYield 92%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 25517Ammonium ChlorideSolvent

Conditions

Temperature
0 °C

Procedure

Dissolve 3,5-dimethylpyrazole (0.331 g, 3.44 mmol) in N,N-dimethylformamide (7 mL) and add sodium hydride (0.165 g, 4.13 mmol). After 10 min., cool to 0° C. and add 4-methoxybenzyl chloride (0.654 mL, 4.82 mmol) dropwise. Stir the mixture at 25° C. for 18 hr. then dilute with saturated ammonium chloride. Extract with ethyl acetate 3 times, dry (sodium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 40:60 hexanes:ethyl acetate), to give 1-(4-methoxybenzyl)-3,5-dimethyl-1H-pyrazole as a colorless oil (0.682 g, 92%). MS (APCI): m/z=217 [M+H].

Workup

  1. extractionExtract with ethyl acetate 3 times
  2. dry with materialdry (sodium sulfate)
  3. filtrationfilter
  4. concentrationconcentrate
  5. custompurify
  6. wash(silica gel chromatography, eluting with 40:60 hexanes:ethyl acetate)

Sources & evidence

ORD record
ord-79bed808bf71472e9b2f85efdd0352d9
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Reaction notes

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