1,4-Dioxane → 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid

HRID 57083Notes

Reaction equation

HRID 57083 reaction equation
[Cl:1][C:2]1[CH:6]=[C:5]([C:7]([O:9]C)=[O:8])[N:4]([C:11]2[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=2)[N:3]=1.O.[OH-].[Li+].O1CCOCC1>O>[Cl:1][C:2]1[CH:6]=[C:5]([C:7]([OH:9])=[O:8])[N:4]([C:11]2[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=2)[N:3]=1

Participants

5

Reactant 3

HCID 312751,4-DioxaneHCID 168937Lithium hydroxide, monohydrateHCID 118022666methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate

Product 1

HCID 917544803-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

In step c of Scheme 2, methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d) is saponified in the presence of an inorganic base, preferably metal hydroxides or their hydrates such as lithium hydroxide hydrate (LiOH.H2O) in water and a polar solvent such as dioxane at temperatures from about 0° C. to about 30° C. to yield 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid (6e). Alternatively, this process can also be accomplished by hydrolysis by exposing methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d) to a concentrated acid such as hydrochloric acid in water at temperatures from about 30° C. to about 100° C.

Sources & evidence

ORD record
ord-9e3e1582f65b40dbbfed1770deba1f9a
Source dataset
uspto-grants-2016_09
Patent number
US09434712B2

Reaction notes

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