Dalinger, I. L. et al. published their research in Izvestiya Akademii Nauk, Seriya Khimicheskaya in 1993 | CAS: 5334-39-4

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 鎺矯).Pyrazole used as a ligand to prepare organometallic compounds. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.Formula: C4H5N3O2

Method for preparation of C-(diformylmethyl)nitropyrazoles was written by Dalinger, I. L.;Shkineva, T. K.;Shevelev, S. A.;Kral, V.;Arnold, Z.;Kanishchev, M. I.. And the article was included in Izvestiya Akademii Nauk, Seriya Khimicheskaya in 1993.Formula: C4H5N3O2 This article mentions the following:

Pyrazoletrimethinium salts have been synthesized by double formylation of the corresponding C-methylnitropyrazoles. Trimethinium hydrolysis of the trimethinium salts leads to C-(diformylmethyl)nitropyrazoles, e.g., I. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4Formula: C4H5N3O2).

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 鎺矯).Pyrazole used as a ligand to prepare organometallic compounds. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.Formula: C4H5N3O2

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics