Carbon Dioxide → 1-Hydroxypyrazole-4-carboxylic acid

HRID 622186Notes

Reaction equation

HRID 622186 reaction equation
[OH:1][N:2]1[CH:6]=[CH:5][CH:4]=[N:3]1.[C:7](=O)([O-:9])[O-:8].[K+].[K+].C(=O)=O.Cl>O>[OH:1][N:2]1[CH:6]=[C:5]([C:7]([OH:9])=[O:8])[CH:4]=[N:3]1

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 313Hydrochloric AcidHCID 11430Potassium CarbonateHCID 30167331-hydroxy-1H-pyrazole

Product 1

HCID 137994111-Hydroxypyrazole-4-carboxylic acidYield 45%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

1 part of 1-hydroxypyrazole is mixed thoroughly with 4 parts of potassium carbonate, and the mixture is introduced into an autoclave. Carbon dioxide is forced in at room temperature until the pressure reaches 50 bar, after which heating is carried out for 20 hours at 150° C. The reactor content is then dissolved in water, the solution is acidified with hydrochloric acid, which precipitates the 1-hydroxypyrazole-4-carboxylic acid, and the latter is filtered off and recrystallized from water. 0.68 part (45% of theory) of 1-hydroxypyrazole-4-carboxylic acid of melting point 230° C. is obtained.

Workup

  1. additionthe mixture is introduced into an autoclave
  2. customis forced in at room temperature until the pressure
  3. temperatureafter which heating
  4. customprecipitates the 1-hydroxypyrazole-4-carboxylic acid
  5. filtrationthe latter is filtered off
  6. customrecrystallized from water

Sources & evidence

ORD record
ord-7f6b44bf592f4323965e02e0a99ba42f
Source dataset
uspto-grants-1988_09
Patent number
US04769473

Reaction notes

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