Potassium Carbonate → Ethyl 5-amino-1-isopropyl-1H-pyrazole-4-carboxylate

HRID 880889

Reaction equation

HRID 880889 reaction equation
[C:1]([C:3](=[CH:9]OCC)[C:4]([O:6][CH2:7][CH3:8])=[O:5])#[N:2].Cl.[CH:14]([NH:17][NH2:18])([CH3:16])[CH3:15].C(=O)([O-])[O-].[K+].[K+]>C(O)C.CO>[NH2:2][C:1]1[N:17]([CH:14]([CH3:16])[CH3:15])[N:18]=[CH:9][C:3]=1[C:4]([O:6][CH2:7][CH3:8])=[O:5]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 789432-Propenoic acid, 2-cyano-3-ethoxy-, ethyl esterHCID 855731-Isopropylhydrazine hydrochloride

Product 1

HCID 22762155Ethyl 5-amino-1-isopropyl-1H-pyrazole-4-carboxylateYield 94%

Reagents, catalysts & solvents 1

HCID 18681192Ethanol, mixt. with methanolSolvent

Procedure

A mixture of ethyl 2-cyano-3-ethoxyacrylate (84.4 g, 0.50 mol), isopropyl hydrazine hydrochloride (55.2 g, 0.50 mol) and potassium carbonate (68.8 g, 0.50 mol) in 90% ethanol/methanol (1.5 L) was heated under reflux for 16 hours. The solvent was then removed in vacuo and water and ethyl acetate were added. The mixture was separated and the organic layer was dried over magnesium sulfate, filtered and the solvent was removed in vacuo to yield ethyl 5-amino-1-isopropyl-1H-pyrazole-4-carboxylate (92.4 g, 94%). +ESI (M+H) 198.1; 1H NMR (400 MHz, CDCl3, δ): 7.63 (s, 1H), 4.97 (br.s., 2H), 4.28 (q, 2H), 4.18 (m, 1H), 1.45 (d, 6H), 1.31 (t, 3H).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 16 hours
  3. customThe solvent was then removed in vacuo and water and ethyl acetate
  4. additionwere added
  5. customThe mixture was separated
  6. dry with materialthe organic layer was dried over magnesium sulfate
  7. filtrationfiltered
  8. customthe solvent was removed in vacuo

Sources & evidence

ORD record
ord-0b3e4109c71d4bcca0c53b10b5358ef9
Source dataset
uspto-grants-2015_03
Patent number
US08993586B2

Linked notes

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