On August 12, 1975, Wikel, James H. published a patent.COA of Formula: C11H9N3O4 The title of the patent was 5-(2-Aminophenyl)pyrazole-3-carboxylic acids and esters. And the patent contained the following:
MeO2CCO2Me was treated with MeCOC6H4NO2-2 and the o-O2NC6H4COCH2COCO2Et cyclized with H2NNH2 to give I (R = NO2), which was reduced to I (R = NH2). At 1-200 mg/kg I (R = NH2) was a complement inhibitor. The experimental process involved the reaction of Methyl 3-(2-nitrophenyl)-1H-pyrazole-5-carboxylate(cas: 57446-04-5).COA of Formula: C11H9N3O4
The Article related to complement inhibitor aminophenylpyrazolecarboxylate, pyrazolecarboxylate aminophenyl complement inhibitor, Heterocyclic Compounds (More Than One Hetero Atom): Pyrazoles and other aspects.COA of Formula: C11H9N3O4
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics