Srinivasan, T. N. et al. published their research in Organic Preparations and Procedures International in 1987 | CAS: 2166-13-4

6-(4-Chlorophenyl)pyridazin-3(2H)-one (cas: 2166-13-4) belongs to pyridazine derivatives. Pyridazine-based compounds continued to be a great source of biologically active compounds as evidenced by the number of publications which emerged in 2021. The activity depends upon the changes of substituted groups in the pyridazine ring system resulting in different biological activities. In addition, the natural pyrimidine bases uracil, thymine, and cytosine, which are constituents of the nucleic acids, are found to be the most important naturally occurring diazines.Electric Literature of C10H7ClN2O

Chlorination of pyridazinones with chlorocarbonyl isocyanate was written by Srinivasan, T. N.;Rao, K. Rama;Sattur, P. B.. And the article was included in Organic Preparations and Procedures International in 1987.Electric Literature of C10H7ClN2O This article mentions the following:

Heating arylpyridazinones I (R = Ph, 4-ClC6H4, etc.) with ClCONCO at 50-65掳 in various solvents (e.g. MeCN) for 4-4.5 h gave 70-73% arylchloropyridazines II. In the experiment, the researchers used many compounds, for example, 6-(4-Chlorophenyl)pyridazin-3(2H)-one (cas: 2166-13-4Electric Literature of C10H7ClN2O).

6-(4-Chlorophenyl)pyridazin-3(2H)-one (cas: 2166-13-4) belongs to pyridazine derivatives. Pyridazine-based compounds continued to be a great source of biologically active compounds as evidenced by the number of publications which emerged in 2021. The activity depends upon the changes of substituted groups in the pyridazine ring system resulting in different biological activities. In addition, the natural pyrimidine bases uracil, thymine, and cytosine, which are constituents of the nucleic acids, are found to be the most important naturally occurring diazines.Electric Literature of C10H7ClN2O

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem