Water → ETHYL 1-METHYL-5-PROPYL-1H-PYRAZOLE-3-CARBOXYLATE

HRID 1278934Notes

Reaction equation

HRID 1278934 reaction equation
[CH3:1][NH:2][NH2:3].O=[C:5]([CH2:12][C:13](=O)[CH2:14][CH2:15]C)[CH2:6][C:7]([O:9][CH2:10][CH3:11])=[O:8].O>C(O)C>[CH3:1][N:2]1[C:12]([CH2:13][CH2:14][CH3:15])=[CH:5][C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[N:3]1

Participants

5

Reactant 3

HCID 962WaterHCID 6061MethylhydrazineHCID 18431642HCID 18431642, compound

Product 1

HCID 11805647ETHYL 1-METHYL-5-PROPYL-1H-PYRAZOLE-3-CARBOXYLATEYield 7.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

10.4 g of methylhydrazine were initially charged in 50 ml of ethanol and, with stirring and external cooling, admixed with a solution of 42.9 g of ethyl 2,4-diketoheptanecarboxylate in 50 ml of ethanol, during which the internal temperature was kept at 5 to 10° C. (time for the dropwise addition: 10 minutes). The solution was stirred at 5 to 10° C. for another 30 minutes, the solvent and the water which had been formed were distilled off and the residue was fractionated under reduced pressure. The desired ethyl 1-methyl-3-n-propyl-pyrazole-5-carboxylate passed over at 125 to 128° C. (13 mm). The yield was 78.3% of theory. By further distillation (166 to 168° C./13 mm), the undesired isomer (=ethyl 1-methyl-5-n-propyl-pyrazole-3-carboxylate) was obtained in a yield of 7.9% of theory. Thus, the isomer ratio was approximately 10:1 in favor of the desired isomer.

Workup

  1. customwas kept at 5 to 10° C.
  2. additionfor the dropwise addition
  3. custom10 minutes
  4. stirringThe solution was stirred at 5 to 10° C. for another 30 minutes
  5. distillationwere distilled off
  6. custompassed over at 125 to 128° C. (13 mm)
  7. distillationBy further distillation (166 to 168° C./13 mm)

Sources & evidence

ORD record
ord-ea96342c93ee4495b99b5776fad0afaf
Source dataset
uspto-grants-2002_09
Patent number
US06444828B1

Reaction notes

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