Acetic Acid → 1,3-dimethyl-1H-indazole-4,5-dicarboxylic acid

HRID 1031026

Reaction equation

C(C1[C:11]([C:12](OCC)=[O:13])=[CH:10][CH:9]=[C:8]2[C:4]=1[C:5]([CH3:18])=[N:6][N:7]2[CH3:17])#N.Br.[C:20]([OH:23])(=[O:22])[CH3:21].[OH2:24]>>[CH3:17][N:7]1[C:8]2[C:4](=[C:21]([C:20]([OH:23])=[O:22])[C:11]([C:12]([OH:13])=[O:24])=[CH:10][CH:9]=2)[C:5]([CH3:18])=[N:6]1

Participants

Reactant 4

HCID 176Acetic Acid

HCID 260Hydrogen Bromide

HCID 962Water

HCID 22402968ethyl 4-cyano-1,3-dimethyl-1H-indazole-5-carboxylate

Product 1

HCID 224029461,3-dimethyl-1H-indazole-4,5-dicarboxylic acidYield 97.8%

Procedure

A mixture of ethyl 4-cyano-1,3-dimethyl-1H-indazole-5-carboxylate (7.03 g, 28.7 mmol), concentrated hydrobromic acid (35 mL) and acetic acid (35 mL) is stirred for 2 hours at reflux temperature, cooled, diluted with water (200 mL) and stirred for 2 hours. Filtration of the reaction mixture affords the title product as a pale blue solid (6.57 g, 97.8%), mp 228.5°-232.5° C.

Workup

temperatureat reflux temperature
temperaturecooled
stirringstirred for 2 hours
filtrationFiltration of the reaction mixture

Sources & evidence

ORD record: ord-b2c14cbcb14847589053b76ff6b66b22
Source dataset: uspto-grants-1992_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05108485

Linked notes

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