Pyridazine Derivatives and Related Compounds Part 5. Pyrazolo[3,4-c]pyridazine: Synthesis and Some Reactions

Pyridazine derivatives and related compounds. Part 141. Photolysis of 3-diazo-4,5-diphenylpyrazolo[3,4-c]pyridazine

“…and superimposable IR) with an authentic sample synthesised unambiguously by acetylation of the 3-amino-4,5-diphenyl-1H-pyrazolo [3,4-c]pyridazine with acetic anhydride. 9 Analogous results were obtained when the diazo compound 1 was irradiated in dimethyl sulfoxide, dimethyl formamide and in morpholine, where 8-10 were produced, respectively. The structures of photoproducts 8-10 were elucidated on the basis of spectral data and analytical results.…”

“…162°C (dec), was prepared from the corresponding 3-amino derivative, as reported previously. 8 General procedure for photochemical reactions A sample of compound 1 in the appropriate anhydrous solvent/ reagent, was irradiated until the starting material disappeared. After removing the solvent under reduced pressure, the residue was recrystallised from an appropriate solvent.…”

Pyridazine derivatives and its related compounds. Part 31. Synthesis of some disperse dyes derived from 3-amino-1H-pyrzolo[3,4-c]pyridazine and their color assessment on polyester fabrics

“…244-245 °C) according to the reported procedures [7] by refluxing 3-chloro-5,6-diphenylpyridazine-4-carbonitrile 1 with hydrazine hydrate for 3 hours, (Scheme 1).…”

“…The synthesis of 3-amino-4,5-diphenyl-1H-pyrazolo [3,4-c]pyridazine 2 (Scheme 1) [7], and azobenzene compounds 3a-e and 4a-i [8], were conducted according to known procedures. Spectral data for compounds 3a-e and 4a-i were described in the previous parts (Scheme 2 and 3) [9,10].…”

2-Substituted-8-methyl-3,6-dihydroimidazo[4,5-c]pyrazolo[3,4-e]pyridazine as an anti-inflammatory agent

“…Heterocyclic systems containing pyrazole and imidazole rings are characterized by several biological properties (Avasthi et al, 2002(Avasthi et al, , 2003 including a medicinal character which can be utilized in the management of inflammation (Deeb et al, , 1991Tisler and Stanounic, 1973;Seada et al, 1989). Various synthetic routes have been followed for synthesizing the fused ring pyrazolo-pyridazine system and their derivatives (Druey, 1958;Caronna et al, 1986;Kobayashi et al, 1971;Kasuga et al, 1974;Shawali, 1977;Kurihara et al, 1980).…”