Thionyl Chloride → 5-fluoro-1-methyl-3-difluoromethyl-1H-pyrazole-4-carbonyl chloride

HRID 1972130Notes

Reaction equation

[F:1][C:2]1[N:6]([CH3:7])[N:5]=[C:4]([CH:8]([F:10])[F:9])[C:3]=1[C:11]([O:13]CC)=O.O=S(Cl)[Cl:18]>C1(C)C=CC=CC=1.[OH-].[Na+]>[F:1][C:2]1[N:6]([CH3:7])[N:5]=[C:4]([CH:8]([F:10])[F:9])[C:3]=1[C:11]([Cl:18])=[O:13]

Participants

Conditions

Temperature: 80 °C

Procedure

A solution of 22.3 g (100 mmol) of ethyl 5-fluoro-1-methyl-3-difluoromethyl-1H-pyrazole-4-carboxylate in 100 ml of toluene and 50 ml of 10% NaOH are stirred at AT for 3 hours. The aqueous phase is separated and adjusted to pH 5 with HCl. After extracting the product with chlorobenzene and azeotropically drying the organic phase, 23.8 g (200 mmol) of SOCl2 are added to the solution and the mixture is heated at 80° C. for 2 hours. After evaporating the reaction mixture, 20.1 g of the product are obtained as an oil with a purity (GC) of 98%.

Workup

customThe aqueous phase is separated
extractionAfter extracting the product with chlorobenzene
additionare added to the solution
customAfter evaporating the reaction mixture, 20.1 g of the product
customare obtained as an oil with a purity (GC) of 98%

Sources & evidence

ORD record: ord-e282464d28ac4e47b39c30adeb72cb11
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08431718B2

Reaction notes

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