Ethanol → 1H-Pyrazole-5-carboxylic acid, 4-iodo-1-methyl-, ethyl ester

HRID 588369

Reaction equation

HRID 588369 reaction equation
[I:1][C:2]1[CH:3]=[N:4][N:5]([CH3:10])[C:6]=1[C:7]([OH:9])=[O:8].[C:11](Cl)(=O)[C:12](Cl)=O.CCO>C(Cl)Cl.CN(C=O)C>[I:1][C:2]1[CH:3]=[N:4][N:5]([CH3:10])[C:6]=1[C:7]([O:9][CH2:11][CH3:12])=[O:8]

Participants

6

Reactant 3

HCID 702EthanolHCID 65578Oxalyl chlorideHCID 6736874-Iodo-1-methyl-1H-pyrazole-5-carboxylic acid

Product 1

HCID 601366981H-Pyrazole-5-carboxylic acid, 4-iodo-1-methyl-, ethyl esterYield 89%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Procedure

4-Iodo-1-methyl-1H-pyrazole-5-carboxylic acid (301.68 g, 1.2 moles) was slurried in 1.2 L of DCM and DMF (2.3 g, 31 mmol) followed by addition of oxalyl chloride (115 mL, 1.3 moles) over 37 minutes and then stirred at room temperature for 3 h. To the resulting solution was added EtOH (750 mL, 12.9 mol) over 5 min followed by stirring at room temperature for 2 h. The crude product solution was concentrated to dryness in vacuo and then reconstituted in 1.2 L of warm heptane followed by filtration. The filtrate was concentrated by removing 500 mL of heptane, resulting in precipitation of solids. The solids were collected via filtration and dried to afford ethyl 4-iodo-1-methyl-1H-pyrazole-5-carboxylate as a white solid (297.6 g, 89% yield).

Workup

  1. stirringby stirring at room temperature for 2 h
  2. concentrationThe crude product solution was concentrated to dryness in vacuo
  3. filtrationfollowed by filtration
  4. concentrationThe filtrate was concentrated
  5. customby removing 500 mL of heptane
  6. customresulting in precipitation of solids
  7. filtrationThe solids were collected via filtration
  8. customdried

Sources & evidence

ORD record
ord-884fe9457511462fa089a6eb1ba3a546
Source dataset
uspto-grants-2016_01
Patent number
US09227956B2

Linked notes

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