Synthesis of 3‐arylazo‐6‐oxopyridazin‐5‐carbonitriles: A versatile precursor for condensed arylazopyridazin‐6‐ones

Abstract

hydrazono]-butan-2-one were produced via coupling the (E) 2-oxopropanal-1-phenylhydrazone or (E) 2-oxobutanal-1-(4-methylphenyl)hydrazone with aromatic diazonium salts. These formazanes condensed readily with ethyl cyanoacetate to yield 5-methyl-3-oxo-2-phenyl-6-phenylazo-2,3-dihydropyridazine-4-carbonitrile compound (9a), 5-ethyl-3-oxo-2-p-tolyl-6-p-tolylazo-2,3-dihydropyridazine-4-carbonitrile and/or 5-ethyl-3-oxo-2,6-di-p-tolyl-2,3-dihydropyridazine-4-carbonitrile that reacted with sulphur in presence of piperidine to yield the aminothienopyridazinones. The latter reacted with electron poor olefins and acetylenes to yield aminophthalazines. Compound (9a) reacted also with benzylidenemalononitrile to yield the arylazophthalazinone.

Disperse Dyes Based on Aminothiophenes: Their Dyeing Applications on Polyester Fabrics and Their Antimicrobial Activity

“…The solid product, so formed, was collected by filtration and crystallized from dioxane. Compound 9 was obtained as brown crystals (80% (11). A mixture of compound 8 (4.44 g, 10 mmol) acetic acid (10 mL) and ammonium acetate (3.45 g, 30 mmol) was refluxed for 3 h. The crude product was poured onto water, the solid product, so formed, was collected by filtration and crystallized from dioxane/ethanol (3:1).…”

“…A number of researchers have studied aminothiophene derivatives as azo disperse dyes in the dyeing of synthetic fibers [3][4][5][6][7] and blended polyester/wool fibers [8], This class of compounds OPEN ACCESS also showed semiconducting properties and more recently, uses in optical data storage devices [9]. The synthesis of arylazothienopyridazines and their benzo-fused derivatives have been recently extensively studied [10,11]. In spite of a large number of reports on the utility of these compounds in the dye industry, to our knowledge, their corresponding arylazothienopyridazines have never been reported as potential monoazo disperse dyes.…”

Formazans in the synthesis of heterocycles. II. Synthesis of azines (Review)

“…It is difficult to stop the condensation of 3-acyl-1,5-diarylformazans 76 with cyanoacetic esters at the stage of (1,5-diarylformazan-3-yl)cyanoacrylic esters (analogs of 3-vinylformazans 74). Immediate intramolecular acylation to 2,3-dihydropyridazin-3-ones 75d in the reaction mass occurs [56].…”

Arylazoazines and arylazoazoles as interesting disperse dyes: Recent developments with emphasis on our contribution laboratory outcomes

“…Other class of arylazoazines has also been synthesized by Al-Mousawi et al [54][55][56]. Thus arylazopyridazinone 27 reacted with DMFDMA affording dihydropyridazine-4-carbonitrile 28 that was readily converted into the pyrido [3,4-d] Acylating of compound 30 in acetic acid resulted in the formation of acetylamino 35.…”