《Effect of a neighboring methyl group on the acid- and base-catalyzed cyclizations of 2-ureidobenzoic acids》 was published in Izvestiya po Khimiya in 1988. These research results belong to Blagoeva, I.; Koedzhikov, A.; Pozharliev, I.. Safety of 4,6-Dichloro-3-phenylpyridazine The article mentions the following:
The cyclization of title compound I (R = H) in acid is 1.6 times slower than that of I (R = Me); in base, however, I (R = H) cyclizes 16 times faster than I (R = Me). The rates are interpreted in terms of resonance stabilization of CO2H but not CO2- and steric hindrance in the transition state. In the base-catalyzed process, a change in rate-determining step occurs as the alkalinity is increased. In the experiment, the researchers used 4,6-Dichloro-3-phenylpyridazine(cas: 40020-05-1Safety of 4,6-Dichloro-3-phenylpyridazine)
4,6-Dichloro-3-phenylpyridazine(cas: 40020-05-1) belongs to pyridazine. The pyridazine moiety is an important structural feature of various pharmacologically important compounds with activities like antimicrobial, sedative-hypnotic, anticonvulsant, analgesic, anti-inflammatory, antiplatelet, anticancer, antisecretory, antiulcer, antidepressant, neuroleptic, immunosuppressant, cardiotonic, vasodilator, antiarrhythmic, and hypocholesterolaemic. Safety of 4,6-Dichloro-3-phenylpyridazine
Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem