Hydrochloric Acid → 4-Formyl-1H-pyrazole-5-carboxylic acid

HRID 1054198Notes

Reaction equation

HRID 1054198 reaction equation
[CH:1]([C:3]1[CH:4]=[N:5][NH:6][C:7]=1[C:8]([O:10]CC)=[O:9])=[O:2].CO.[OH-].[Na+].Cl>O>[CH:1]([C:3]1[CH:4]=[N:5][NH:6][C:7]=1[C:8]([OH:10])=[O:9])=[O:2]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 887MethanolHCID 14798Sodium HydroxideHCID 713076ethyl 4-formyl-1H-pyrazole-3-carboxylate

Product 1

HCID 224781464-Formyl-1H-pyrazole-5-carboxylic acidYield 75%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

To a suspension of ethyl 4-formyl-1H-pyrazole-5-carboxylate (SM2-B, 19 g, 115 mmol) in a solution of MeOH (76 ml) and water (130 mL) was added NaOH (14 g, 345 mmol) in water (130 mL) at 0° C. The reaction mixture was warmed to rt and stirred for 2 h. The solution was adjusted to pH of 1 with concentrated hydrochloride. The solid was collected, washed with water (50 mL), and dried in air to give the product (4-B) (12 g, 75%) as a light yellow solid. 1H NMR (300 MHz, DMSO): δ 8.45 (s, 1H), 10.29 (s, 1H). LC-MS (M+H)+=141.

Workup

  1. customThe solid was collected
  2. washwashed with water (50 mL)
  3. customdried in air

Sources & evidence

ORD record
ord-f9c466d61af34f7d893c550d7da72682
Source dataset
uspto-grants-2016_07
Patent number
US09394296B2

Reaction notes

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