Acetic Anhydride → 1,3-Dimethyl-1H-indazole-4,5-dicarboxylic anhydride

HRID 259728

Reaction equation

[CH3:1][N:2]1[C:10]2[C:5](=[C:6]([C:14]([OH:16])=[O:15])[C:7]([C:11](O)=[O:12])=[CH:8][CH:9]=2)[C:4]([CH3:17])=[N:3]1.C(OC(=O)C)(=O)C>>[CH3:1][N:2]1[C:10]2[C:5](=[C:6]3[C:14](=[O:16])[O:15][C:11](=[O:12])[C:7]3=[CH:8][CH:9]=2)[C:4]([CH3:17])=[N:3]1

Participants

Reactant 2

HCID 7918Acetic Anhydride

HCID 224029461,3-dimethyl-1H-indazole-4,5-dicarboxylic acid

Product 1

HCID 541895841,3-Dimethyl-1H-indazole-4,5-dicarboxylic anhydride

Conditions

Temperature: 5 °C

Procedure

A mixture of 1,3-dimethyl-1H-indazole-4,5-dicarboxylic acid (6.30 g, 26.9 mmol) and acetic anhydride is stirred at reflux temperature for 3 hours, cooled to 5° C. and filtered. The filter cake is air-dried to give the title product as chartreuse needles (4.80 g, 82.5%), mp 214°-215.5° C.

Workup

temperatureat reflux temperature for 3 hours
filtrationfiltered
customThe filter cake is air-dried

Sources & evidence

ORD record: ord-5182e73af48c499c9ebc0f2917465cda
Source dataset: uspto-grants-1996_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05523279

Linked notes

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