Hydrochloric Acid → 4-Chloro-3-methyl-1H-pyrazole-5-carboxylic acid

HRID 528935

Reaction equation

HRID 528935 reaction equation
[Cl:1][C:2]1[C:3]([C:8]([O:10]CC)=[O:9])=[N:4][NH:5][C:6]=1[CH3:7].[OH-].[Na+].Cl>CO.C1COCC1>[Cl:1][C:2]1[C:3]([C:8]([OH:10])=[O:9])=[N:4][NH:5][C:6]=1[CH3:7]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 604759ethyl 4-chloro-5-methyl-1H-pyrazole-3-carboxylate2×

Product 1

HCID 176889814-Chloro-3-methyl-1H-pyrazole-5-carboxylic acidYield 87.3%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of ethyl 4-chloro-5-methyl-1H-pyrazole-3-carboxylate (Intermediate 1A, 2.01 g, 10.7 mmol) in MeOH (8.2 mL) and THF (8.2 mL) was added 2N aq. NaOH solution (27 mL, 53.3 mmol). The reaction mixture was stirred at room temperature overnight, then cooled to 0° C. and neutralized with 1N aq. HCl solution (pH=3-4). The resulting solid was collected by filtration and washed with water to give the title compound (1.50 g, 87%) as a white solid. 1H NMR (DMSO-d6) δ 2.19 (br s, 3H); MS (ESI+) m/z 160.9 (M+H)+.

Workup

  1. filtrationThe resulting solid was collected by filtration
  2. washwashed with water

Sources & evidence

ORD record
ord-1e0a740b74704675bb6831cfb7f6da09
Source dataset
uspto-grants-2016_05
Patent number
US09346795B2

Linked notes

Loading…