Thionyl Chloride → Ethyl 5-(chlorocarbonyl)-1-ethyl-1H-pyrazole-4-carboxylate

HRID 1958331Notes

Reaction equation

HRID 1958331 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:10]=[N:9][N:8]([CH2:11][CH3:12])[C:7]=1[C:13]([OH:15])=O)=[O:5])[CH3:2].S(Cl)([Cl:18])=O>>[Cl:18][C:13]([C:7]1[N:8]([CH2:11][CH3:12])[N:9]=[CH:10][C:6]=1[C:4]([O:3][CH2:1][CH3:2])=[O:5])=[O:15]

Participants

3

Reactant 2

HCID 24386Thionyl ChlorideHCID 670418082-Ethyl-2H-pyrazole-3,4-dicarboxylic acid 4-ethyl ester

Product 1

HCID 86657899Ethyl 5-(chlorocarbonyl)-1-ethyl-1H-pyrazole-4-carboxylateYield 100.1%

Procedure

2-Ethyl-2H-pyrazole-3,4-dicarboxylic acid 4-ethyl ester (example 62, step 3, 1.47 g, 6.93 mmol) and thionyl chloride (19.0 g, 11.6 ml, 159 mmol) were combined to give a light yellow solution. The reaction mixture was stirred at reflux for 5 h. Excess thionyl chloride was removed under reduced pressure, and residual thionyl chloride was removed under vacuum. The title compound (1.6 g, estimated purity 37%, 37% yield) was used without further purification in the next step. MS (m/e)=390.3 [M+H+].

Workup

  1. customto give a light yellow solution
  2. temperatureat reflux for 5 h
  3. customExcess thionyl chloride was removed under reduced pressure, and residual thionyl chloride
  4. customwas removed under vacuum

Sources & evidence

ORD record
ord-39fdb4f1650248dea3eb5a0f4e76df6c
Source dataset
uspto-grants-2013_04
Patent number
US08410117B2

Reaction notes

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