Chlorine → 3-(3-fluoro-5-chloro-2-pyridyl)-4-chloro-5-difluoromethoxy-1-methyl-[1H]-pyrazole

HRID 1532570Notes

Reaction equation

[F:1][C:2]1[C:3]([C:9]2[CH:13]=[C:12]([O:14][CH:15]([F:17])[F:16])[N:11]([CH3:18])[N:10]=2)=[N:4][CH:5]=[C:6]([Cl:8])[CH:7]=1.C([O-])(=O)C.[Na+].[Cl:24]Cl>C(O)(=O)C>[F:1][C:2]1[C:3]([C:9]2[C:13]([Cl:24])=[C:12]([O:14][CH:15]([F:16])[F:17])[N:11]([CH3:18])[N:10]=2)=[N:4][CH:5]=[C:6]([Cl:8])[CH:7]=1

Participants

Conditions

Temperature: 60 °C

Procedure

17.92 g of 3-(3-fluoro-5-chloro-2-pyridyl)-5-difluoromethoxy-1-methyl-[1H]-pyrazole (Example H15) are initially introduced into 60 ml of glacial acetic acid together with 10.6 g of sodium acetate. The mixture is heated up to 60° C., while stirring, and a saturated solution of chlorine in glacial acetic acid is added until TLC analysis of a worked-up sample shows a complete conversion (silica gel 60 F254; eluting agent: n-hexane/ethyl acetate 2/1; UV; Rf value of the starting material 0.34; Rf value of the product 0.48). The mixture is then concentrated to dryness in vacuo and the resulting residue is partitioned between sodium bicarbonate solution and ethyl acetate. The organic phase is washed with brine, dried over sodium sulfate, filtered and evaporated to dryness in vacuo. 19.8 g of the desired target compound (pure according to TLC) are obtained. Melting point 95-96° C.

Workup

washeluting agent
concentrationThe mixture is then concentrated to dryness in vacuo
customthe resulting residue is partitioned between sodium bicarbonate solution and ethyl acetate
washThe organic phase is washed with brine
dry with materialdried over sodium sulfate
filtrationfiltered
customevaporated to dryness in vacuo
custom19.8 g of the desired target compound (pure according to TLC) are obtained

Sources & evidence

ORD record: ord-018f15d45ff24099aa533cdcb290c29d
Source dataset: uspto-grants-2001_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06204221B1

Reaction notes

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