Hydrochloric Acid → ethyl 3-amino-1-methyl-1H-pyrazole-4-carboxylate

HRID 2246765Notes

Reaction equation

HRID 2246765 reaction equation
Cl.C(=[N:9][N:10]([CH:12]=[C:13]([C:19]#[N:20])[C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH3:11])C1C=CC=CC=1>C(O)C>[NH2:20][C:19]1[C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[CH:12][N:10]([CH3:11])[N:9]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 3751881ethyl 3-(N'-benzylidene-N-methylhydrazino)2-cyanoacrylate

Product 1

HCID 252927ethyl 3-amino-1-methyl-1H-pyrazole-4-carboxylateYield 103%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

At room temperature, 100 ml of concentrated hydrochloric acid were added dropwise over a period of 20 min to a suspension of 220 g (0.855 mol) of ethyl 3-(N′-benzylidene-N-methylhydrazino)2-cyanoacrylate (XVI-1) in 1000 ml of ethanol. The mixture was then heated at the boil for 1 hour. After removal of the solvent, the oily residue was triturated with gentle heating with 200 ml of diethyl ether, resulting in the precipitation of a solid. Filtration with suction gave 149 g (95% of theory) of ethyl 3-amino-1-methyl-1H-pyrazole-4-carboxylate [logP (pH 2.3)=0.72].

Workup

  1. temperatureThe mixture was then heated at the boil for 1 hour
  2. customAfter removal of the solvent
  3. customthe oily residue was triturated
  4. temperaturewith gentle heating with 200 ml of diethyl ether
  5. customresulting in the precipitation of a solid
  6. filtrationFiltration with suction

Sources & evidence

ORD record
ord-da18b350f346499bb70c2812e79e0f82
Source dataset
uspto-grants-2010_03
Patent number
US07687531B2

Reaction notes

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