390375-69-6Relevant articles and documents
Chemistry of 2-arylhydrazonopropanals: Novel synthesis of 1,6-dihydropyridazines and 5-heteroaryl substituted pyrazolo[1,5-a]pyrimidines and pyrazolo[3,4-b]pyridines
Abdel-Khalik,Agamy,Elnagdi
, p. 1861 - 1865 (2001)
The reaction of 2-arylhydrazonopropanals 1a-d with dimethyl acetylenedicarboxylate in anhydrous dichloromethane in the presence of triphenylphosphine afforded 1,6-dihydropyridazines 2a-d. Compound 1a reacted with dimethyl acetylenedicarboxylate in refluxing acetic acid yielding the corresponding Michael adduct 4. Whereas compound 1d failed to react in acetic acid with diphenylacetylene, its reaction with the same reagent in anhydrous dichloromethane in the presence of triphenylphosphine afforded the Michael adduct 3. Compounds 2b-d reacted with hydrazine hydrate affording the corresponding pyridazino[3,4-d]pyridazines 6b-d. 2-Arylhydrazonopropanals 1a,b reacted with 5-methyl-1H-pyrazol-3-amine in ethanol yielding the corresponding condensation products 8a,b, which cyclized to the 7-substituted 2-methyl-6-phenylazopyrazolo[1,5-a]pyrimidines 9a,b and 4-substituted 3-methyl-5-phenylazopyrazolo[3,4-b]pyridines 10a,b on refluxing in acetic acid. 2-Phenylhydrazonopropanal 1a reacted with p-benzoquinone yielding the resorcinol derivative 12.
