Mitra, P. et al. published their research in Journal of the Indian Chemical Society in 1984 | CAS: 51395-52-9

4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 °C).Pyrazole used as a ligand to prepare organometallic compounds. The pyrazole ring is resistant to oxidation and reduction but the groups, such as alkyl and formyl attached to the ring, are oxidized to respective acids. Only electrolytic oxidation, ozonolysis, and a strong base cause ring opening.Electric Literature of C4H5BrN2O

Heterocyclic fungicides. Part IV was written by Mitra, P.;Mittra, A. S.. And the article was included in Journal of the Indian Chemical Society in 1984.Electric Literature of C4H5BrN2O This article mentions the following:

Thiazolidones I [R = Ph, C6H4OMe, C6H4NO2, C6H4OH, C6H3(OH)OMe, CH:CHPh, C6H4NMe2, furyl] condensed with bromopyrazolinones II (R1 = H, Ph) to give thiazolidonylpyrazolinones III. At 1000 ppm, III gave 28.0-66.0% inhibition of spore germination for P. oryzae and H. oryzae. The most effective compounds were III (R = Ph, C6H4NO2-2, CH:CHPh, R1 = H, Ph; R = C6H4NO2-3, C6H4OMe, R1 = Ph), with 51.4-66.0% germination inhibition for both fungi at 1000 ppm. In the experiment, the researchers used many compounds, for example, 4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9Electric Literature of C4H5BrN2O).

4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 °C).Pyrazole used as a ligand to prepare organometallic compounds. The pyrazole ring is resistant to oxidation and reduction but the groups, such as alkyl and formyl attached to the ring, are oxidized to respective acids. Only electrolytic oxidation, ozonolysis, and a strong base cause ring opening.Electric Literature of C4H5BrN2O

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