Hydrochloric Acid → ethyl 1-methyl-1H-pyrazole-4-carboxylate

HRID 1068389Notes

Reaction equation

HRID 1068389 reaction equation
N(OC(C)(C)C)=O.N[C:9]1[N:13]([CH3:14])[N:12]=[CH:11][C:10]=1[C:15]([O:17][CH2:18][CH3:19])=[O:16].Cl.O>CN(C=O)C>[CH3:14][N:13]1[CH:9]=[C:10]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH:11]=[N:12]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 10906Tert-Butyl nitriteHCID 271299Ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate

Product 1

HCID 11116265ethyl 1-methyl-1H-pyrazole-4-carboxylateYield 91.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
30 °C

Procedure

To a solution of 90% t-butyl nitrite (50 mL, 0.37 mol) in 200 mL DMF was added in portions ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate (39 g, 0.23 mol), maintaining the temperature at around 30° C. After the addition, the resulting mixture was warmed to 50° C. and stirred at that temperature for 0.5 h. The mixture was poured into 100 mL conc HCl and 40 mL water and extracted with CH2Cl2. The organic solution was washed with water, brine, dried and concentrated. Vacuum distillation of the residue gave 32.4 g of ethyl 1-methyl-1H-pyrazole-4-carboxylate as a clear liquid. b.p. 65-80° C. at 0.1 torr.

Workup

  1. additionAfter the addition
  2. temperaturethe resulting mixture was warmed to 50° C.
  3. extractionextracted with CH2Cl2
  4. washThe organic solution was washed with water, brine
  5. customdried
  6. concentrationconcentrated
  7. distillationVacuum distillation of the residue

Sources & evidence

ORD record
ord-94843fe8633547229981c23eabe5fb70
Source dataset
uspto-grants-2001_06
Patent number
US06248894B1

Reaction notes

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