Triethylamine → ethyl 1-butyl-5-methyl-1H-pyrazole-3-carboxylate

HRID 2283731Notes

Reaction equation

HRID 2283731 reaction equation
C(O)(=O)C(O)=O.[CH2:7]([NH:11][NH2:12])[CH2:8][CH2:9][CH3:10].O=[C:14]([CH2:20][C:21](=O)[CH3:22])[C:15]([O:17][CH2:18][CH3:19])=[O:16].C(N(CC)CC)C>C(O)C>[CH2:7]([N:11]1[C:21]([CH3:22])=[CH:20][C:14]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[N:12]1)[CH2:8][CH2:9][CH3:10]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 69208Ethyl 2,4-dioxovalerateHCID 162021Butylhydrazine oxalate

Product 1

HCID 66958271ethyl 1-butyl-5-methyl-1H-pyrazole-3-carboxylateYield 61.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Butylhydrazine oxalate (25 g, 140 mmol) was added over a period of 15 minutes to a solution of ethyl 2,4-dioxovalerate (22.2 g, 140 mmol) and triethylamine (210 mmol) in ethanol (140 mL). The resulting solution was stirred overnight at ambient temperature and concentrated under reduced pressure. Hexane was added, and an insoluble solid was removed by filtration. The hexane was removed under reduced pressure; the residue was purified by chromatography on a HORIZON HPFC system (65I cartridge, eluting with hexanes/ethyl acetate in a gradient from 80:20 to 45:55) to provide 18.1 g of ethyl 1-butyl-5-methyl-1H-pyrazole-3-carboxylate as a pale yellow oil.

Workup

  1. concentrationconcentrated under reduced pressure
  2. additionHexane was added
  3. customan insoluble solid was removed by filtration
  4. customThe hexane was removed under reduced pressure
  5. customthe residue was purified by chromatography on a HORIZON HPFC system (65I cartridge
  6. washeluting with hexanes/ethyl acetate in a gradient from 80:20 to 45:55)

Sources & evidence

ORD record
ord-4df09fe7d88b41e69787d76b35dd8c12
Source dataset
uspto-grants-2015_09
Patent number
US09145410B2

Reaction notes

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