Hydrochloric Acid → Ethyl 4-amino-5-mesityl-1-methyl-1H-pyrazole-3-carboxylate

HRID 321977

Reaction equation

HRID 321977 reaction equation
O=[C:2]([C:8](=[N:20]O)[C:9](=O)[C:10]1[C:15]([CH3:16])=[CH:14][C:13]([CH3:17])=[CH:12][C:11]=1[CH3:18])[C:3]([O:5][CH2:6][CH3:7])=[O:4].Cl.[CH3:23][NH:24][NH2:25]>CO>[NH2:20][C:8]1[C:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])=[N:25][N:24]([CH3:23])[C:9]=1[C:10]1[C:15]([CH3:16])=[CH:14][C:13]([CH3:17])=[CH:12][C:11]=1[CH3:18]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 6061MethylhydrazineHCID 178418386HCID 178418386, compound

Product 1

HCID 15516666Ethyl 4-amino-5-mesityl-1-methyl-1H-pyrazole-3-carboxylateYield 78.9%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of the product of step B (4.0 g, 13.8 mmol) and 1.6 mL of 12N hydrochloric acid in 100 mL of methanol was added dropwise 0.63 g of methyl hydrazine at 0° C. The reaction mixture was stirred at room temperature 4 hours, and then concentrated. The resulting residue was partitioned between water and ethyl acetate. The organic phase was separated and washed once with brine. The ethyl acetate solution was then mixed with 100 mL of water. Solid Na2S2O4 in excess was added in small portion until TLC showed completion of the reduction. The organic phase was separated, washed with water and brine, and dried over Na2SO4. Evaporation gave 3.1 g of the title compound as a foam.

Workup

  1. concentrationconcentrated
  2. customThe resulting residue was partitioned between water and ethyl acetate
  3. customThe organic phase was separated
  4. washwashed once with brine
  5. additionThe ethyl acetate solution was then mixed with 100 mL of water
  6. additionSolid Na2S2O4 in excess was added in small portion until TLC
  7. customThe organic phase was separated
  8. washwashed with water and brine
  9. dry with materialdried over Na2SO4
  10. customEvaporation

Sources & evidence

ORD record
ord-b5c489fc110c41c083188f43d85e9768
Source dataset
uspto-grants-2001_04
Patent number
US06211187B1

Linked notes

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