Ethanol → Ethyl 3-(difluoromethyl)-1-(2-propenyl)-1H-pyrazole-4-carboxylate

HRID 1588780Notes

Reaction equation

HRID 1588780 reaction equation
[OH-].[K+].[F:3][CH:4]([F:13])[C:5]1[C:9]([C:10]([OH:12])=[O:11])=[CH:8][NH:7][N:6]=1.[CH2:14](Br)[CH:15]=[CH2:16].[CH2:18](O)[CH3:19]>>[F:13][CH:4]([F:3])[C:5]1[C:9]([C:10]([O:12][CH2:18][CH3:19])=[O:11])=[CH:8][N:7]([CH2:14][CH:15]=[CH2:16])[N:6]=1

Participants

5

Reactant 4

HCID 702Ethanol2×HCID 7841Allyl bromideHCID 14797Potassium HydroxideHCID 178524804HCID 178524804, compound

Product 1

HCID 19754742Ethyl 3-(difluoromethyl)-1-(2-propenyl)-1H-pyrazole-4-carboxylate

Procedure

To a solution of potassium hydroxide (3.5 g) in ethanol (50 mL) at 0° C. was added dropwise the ethyl ester of 3-(difluoromethyl)-1H-pyrazole-4-carboxylic acid (10.1 g) in ethanol (50 mL), followed by dropwise addition of allyl bromide (4.6 mL). The mixture was stirred overnight, partitioned between ether and 2N HCl. The ether layer was dried (MgSO4) and concentrated in vacuo leaving an oil (11.4 g). The oil was distilled (Kugelrohr 80-85 ° C., 0.3 mm) to give the isomer of the desired product as an oil (2.6 g). Distillation was continued (100-105 ° C., 0.3 mm) to give the desired compound as a clear colorless oil (8.0 g).

Workup

  1. custompartitioned between ether and 2N HCl
  2. dry with materialThe ether layer was dried (MgSO4)
  3. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-335b7abd461b46faa4fe4083b475eb95
Source dataset
uspto-grants-1993_06
Patent number
US05223526

Reaction notes

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