diethyl 1H-pyrazole-3,5-dicarboxylate → diethyl 4-chloro-1H-pyrazole-3,5-dicarboxylate

HRID 2046230Notes

Reaction equation

HRID 2046230 reaction equation
[Cl:1][O-].[Na+].[NH:4]1[C:8]([C:9]([O:11][CH2:12][CH3:13])=[O:10])=[CH:7][C:6]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[N:5]1>CC(O)=O>[CH2:12]([O:11][C:9]([C:8]1[C:7]([Cl:1])=[C:6]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[NH:5][N:4]=1)=[O:10])[CH3:13]

Participants

4

Reactant 2

HCID 142184diethyl 1H-pyrazole-3,5-dicarboxylateHCID 23665760Sodium Hypochlorite

Product 1

HCID 67975929diethyl 4-chloro-1H-pyrazole-3,5-dicarboxylateYield 77.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Sodium hypochlorite (2.79 mL, 5.89 mmol) was added to a solution of diethyl 3,5-pyrazoledicarboxylate (0.5 g, 2.36 mmol) in AcOH (10 mL) and the mixture was stirred at room temperature for 16 hours. Then, the solvent was evaporated in vacuo and the mixture was acidified with a 1N solution of HCl and extracted with AcOEt. The organic layer was separated, dried (MgSO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; MeOH in DCM 0/100 to 05/95). The desired fractions were collected and the solvents evaporated in vacuo to yield 4-chloro-1H-pyrazole-3,5-dicarboxylic acid diethyl ester (450 mg, 66% yield) as a white solid.

Workup

  1. customThen, the solvent was evaporated in vacuo
  2. extractionextracted with AcOEt
  3. customThe organic layer was separated
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. customthe solvents evaporated in vacuo
  7. customThe crude product was purified by flash column chromatography (silica; MeOH in DCM 0/100 to 05/95)
  8. customThe desired fractions were collected
  9. customthe solvents evaporated in vacuo

Sources & evidence

ORD record
ord-02ea0c77547f417f802fc233d7a234f6
Source dataset
uspto-grants-2013_11
Patent number
US08592422B2

Reaction notes

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