Pyridazine Derivatives and Related Compounds, Part 3 [1] Some Reactions with 4-Cyano-3(2H)-pyridazinethione

Abstract

The reaction of 5-amino-3,4-diphenylthieno[2,3-c]pyridazine-6-carboxamide 2 with formamide, acetic anhydride and carbon disulphide yielded pyrimido[4′,5′ :4,5]thieno[2,3-c]-pyridazin-4-one derivatives. Pyrimido[4,5-c]pyridazinethione and dithione derivatives were obtained by cyclocondensation of 3-amino-5,6-diphenylpyridazine-4-carbonitrile (8) with phenyl isothiocyanate and carbon disulphide, respectively. Tetrahydropyridazino[3,4-b]-quinoline (11) was prepared by reaction of 8 with cyclohexanone in presence of zinc chloride.

Synthesis, Reactions and Antimicrobial Activity of Thieno[2,3-c]pyridazine Derivatives

“…Compounds (1, 2, 12, 13, 14 and 15) were prepared by the reported methods. 7,8,9,10,4,3' : 4,5]thieno [2,3-c] ethanol (20 mL), sodium cyanide (0.074 g, 1.5 mmol) was added.…”

“…In the second track study, the pyrimido [4', 5' : 4, 5]thieno [2, 3-c]pyridazine derivative (13) was prepared according to previously described procedure. 9,10 Starting from 5-amino-3, 4-diphenylthieno [2, 3-c]pyridazine-6-carboxamide ( 12) and formamide or formic acid. Upon treatment with phosphorus oxychloride, (13) afforded the 8-chloro derivative (14), 10 which exhibited a remarkable reactivity of its 8-chloro substituent towards nucleophilic agents, thus affording the new 8-substituted pyrimido [4', 5' : 4, 5]-thieno [2, 3-c] pyridazine derivatives (16a-g) and (17a,b) (Scheme 4).…”

Synthesis and antimicrobial activity of some new triazino-, triazolo-, and pyrazolopyridazine derivatives

“…3-Phenyl-1-(4,5,6-triphenylpyridazin-3-yl)-1H-pyrazol-5-ol (11). A mixture of compound 3 (0.01 mol) and ethyl benzoylacetate (0.01 mol) was heated on an oil bath at 160-170°C for 1 h, then cooled, the residue was triturated with petroleum ether at 60-80°C, and the solid precipitated was filtered off, dried, and crystallized from benzene.…”

Synthesis of New Thieno- and Pyrazolo- pyridazine Derivatives

“…In continuation of our studies [1][2][3][4][5][6] directed towards synthesis of new pyridazines annelated with various five and six membered heterocycles, we report here the synthesis of thieno-and pyrazolo-pyridazines likely to possess biologically active compounds. The starting material 3-oxo-5,6-di(pyridin-2yl)-2,3-dihydropyridazine-4-carbonitrile 1 has been prepared via the reaction of 2,2'-pyridil monohydrazone with ethyl cyanoacetate in refluxing sodium ethoxide.…”