Water → 4-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester

HRID 517077Notes

Reaction equation

[CH3:1][O:2][C:3]([C:5]1[CH:9]=[CH:8][N:7]([CH:10]([F:12])[F:11])[N:6]=1)=[O:4].[Cl:13]N1C(=O)CCC1=O.O>CN(C)C=O>[CH3:1][O:2][C:3]([C:5]1[C:9]([Cl:13])=[CH:8][N:7]([CH:10]([F:12])[F:11])[N:6]=1)=[O:4]

Participants

Conditions

Temperature: 50 °C

Procedure

A mixture of 1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester (535 mg, 3 mmol) and N-chloro-succinimide (1.22 g, 9.1 mmol) in N,N-dimethylformamide (5 ml) was heated at 50° C. overnight. The reaction mixture was cooled, poured into water (20 ml), then extracted with ethyl acetate. The organic layer was separated, washed with water, dried over sodium sulphate, finally evaporated at reduced pressure. The yellowish crude material was purified by chromatography on silica gel using a 3:1-mixture of cyclohexane and ethyl acetate as the eluent. The 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester was obtained as a white solid (540 mg, 84% of theory). MS (ISP): m/z=209.9 [M]+.

Workup

temperatureThe reaction mixture was cooled
extractionextracted with ethyl acetate
customThe organic layer was separated
washwashed with water
dry with materialdried over sodium sulphate
customfinally evaporated at reduced pressure
customThe yellowish crude material was purified by chromatography on silica gel using a 3

Sources & evidence

ORD record: ord-4fe3a6ce42144494a5a633d863cfd00f
Source dataset: uspto-grants-2015_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09115098B2

Reaction notes

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