o-Chloranil → ethyl 4-cyano-1,3-dimethyl-1H-indazole-5-carboxylate

HRID 1463217Notes

Reaction equation

HRID 1463217 reaction equation
[C:1]([C:3]1[C:4]2[C:5]([CH3:18])=[N:6][N:7]([CH3:17])[C:8]=2[CH2:9][CH2:10][C:11]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13])#[N:2].C1(Cl)C(Cl)=C(Cl)C(=O)C(=O)C=1Cl>C1C=CC=CC=1>[C:1]([C:3]1[C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[CH:10][CH:9]=[C:8]2[C:4]=1[C:5]([CH3:18])=[N:6][N:7]2[CH3:17])#[N:2]

Participants

4

Reactant 2

HCID 73252o-ChloranilHCID 22402928ethyl 4-cyano-6,7-dihydro-1,3-dimethyl-1H-indazole-5-carboxylate

Product 1

HCID 22402968ethyl 4-cyano-1,3-dimethyl-1H-indazole-5-carboxylateYield 47.3%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A mixture of ethyl 4-cyano-6,7-dihydro-1,3-dimethyl-1H-indazole-5-carboxylate (13.5 g, 55.0 mmol), o-chloranil (16.3 g, 66.0 mmol) and dry benzene is stirred for 1.5 hours at reflux temperature, cooled and filtered. The filtrate is concentrated in vacuo, filtered through two pads of neutral alumina and evaporated to dryness to afford a yellow solid. Recrystallization from ethyl acetate affords the title product (6.33 g, 47.2%), mp 170°-175.5° C.

Workup

  1. temperatureat reflux temperature
  2. temperaturecooled
  3. filtrationfiltered
  4. concentrationThe filtrate is concentrated in vacuo
  5. filtrationfiltered through two pads of neutral alumina
  6. customevaporated to dryness
  7. customto afford a yellow solid
  8. customRecrystallization from ethyl acetate

Sources & evidence

ORD record
ord-a532c404b2d14e46975e091be15fca4a
Source dataset
uspto-grants-1994_04
Patent number
US05300479

Reaction notes

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