Hydrochloric Acid → 5-(2-chloro-4-fluorophenyl)-1,3-dimethyl-1H-pyrazole-4-carboxylic acid

HRID 2276009Notes

Reaction equation

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

Participants

Conditions

Temperature: 0 °C

Procedure

A mixture of methyl 5-(2-chloro-4-fluorophenyl)-1,3-dimethyl-1H-pyrazole-4-carboxylate (i.e. the product of Step C) (12.33 g, 43.7 mol) and sodium hydroxide (1 N, 70 mL) in methanol (70 mL) was heated at reflux for 2 h. The reaction mixture was cooled to about 0° C., and then the pH of the reaction mixture was adjusted to 3 by the addition of aqueous hydrochloric acid solution (1 N). The reaction mixture was extracted with ethyl acetate (3×70 mL) and the combined extracts were washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to provide the title compound as a white solid (11.14 g).

Workup

temperaturewas heated
temperatureat reflux for 2 h
extractionThe reaction mixture was extracted with ethyl acetate (3×70 mL)
washthe combined extracts were washed with saturated aqueous sodium chloride solution
dry with materialdried over magnesium sulfate
filtrationfiltered
concentrationThe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record: ord-396017ac24734bf7a5ee199a66275d1f
Source dataset: uspto-grants-2015_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09131693B2

Reaction notes

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