Ebtisam Abdel Aziz Hafez

α-Enones in heterocyclic synthesis, Part I. Classical synthetic and environmentally friendly synthetic approaches to alkyl and acyl azoles and azines

The utility of 1-N,N-dimethylaminopent-1-en-3-one and 1-(4-acetylphenyl)-3-dimethyl aminopropenone in the synthesis of several new azolotriazine, pyrazolo[3,4-d]pyridazine, isoxazolo[3,4-d]pyridazine, azolopyrimidine and pyridine derivatives by conventional heat and also on microwave irradiation, is reported.

Enaminonitriles in heterocyclic synthesis: new routes for the synthesis of some novel azolo(1,5- a)pyrimidine, pyrimido(1,2-a)benzimidazole, pyrido(1,2-a)benimdazole, pyrazolo(3,4-b)pyridine, pyrazole and pyrimidine derivatives

The synthesis of several new azolo[1,5-a]pyrimidines, pyrimido[1,2-a]benzimidazoles, pyrazolo[3,4-b]pyridines, pyrido[1,2-a]benzimidazoles, pyrazoles and pyrimidines is reported.

Studies with functionally substituted heteroaromatics: a new routes for synthesis of pyridazino[2,3-a] quinazoline and pyridazino-6-imine derivatives

Enaminones couple with diazotized anthranilic acid derivatives yielding 2-arylhydra-zonopropanals that condensed with active methylenes yielding condensed pyridazines.

Substituted hydrazonals as building blocks in heterocyclic synthesis: a new route to arylhydrazonocinnolines

2-heteroylhydrazonopropanals 2a–e and 3-oxo-2-arylhydrazonopropanals 2f–k were prepared via coupling of enaminones 1 with aromatic diazonium salts. Compounds 2a–c condensed with hydrazine hydrate to yield the corresponding hydrazones 3a–c which afford on cyclisation the cinnoline derivatives 6a–c, while condensation of 2g, j with hydrazine hydrate directly yielded the pyrazole derivatives 4g–j. Condensation of 2a–c, f, g with phenyl hydrazine gave the corresponding phenyl hydrazone derivatives 7a–c, f, g. Structures of 2a, h and 3a were assessed by single crystal X-ray analyses.

Activated Nitriles in Heterocyclic Synthesis: The Reaction of Substituted Cinnamonitriles with 2-Functionally Substituted Methyl-2-thiazolin-4-one Derivatives

Abstract A variety of thiazolo[2,3-a]pyridine and 3-(2-thiazolin-2-yl)pyridine derivatives were synthesised via the reaction of arylsubstituted cinnamonitrile derivatives with 2-functionally substituted 2-thiazolin-4-one derivatives. Thiazolo[2,3-a]pyridines were also obtained on reacting arylsubstituted cinnamonitriles with thioglycolic acid in ethanolic triethylamine solutions.

Enaminones in Heterocyclic Synthesis: A Novel Route to Polyfunctionalized Substituted Thiophene, 2,3-Dihydro-1,3,4-Thiadiazole and Naphtho[1,2- b ] Furan Derivatives

The enaminones 1a , b reacted with phenylisothiocyanate to afford the thioanilides 2a , b . The latter could be utilized to synthesize several new polysubstituted thiophenes 9a-f , and 1,3,4-thiadiazoles 12a-f .

Reactions with the Arylhydrazones of α-Cyanoketones: Utility of Arylhydrazonomesoxalonitriles for the Synthesis of Azoles and Azolines

The arylhydrazonomesoxalonitriles derivatives 1 a - c were utilised for the synthesis of several new pyrimidine, pyridines, triazine and isoxazole derivatives. Compound 1 a reacted with alkyl halides to yield the N-alkyl derivatives 12a, b. The latter reacted with hydrazines to yield the amidrazones 13 a, b.

Studies on 3,5-diaminopyrazole derivatives

The behaviour of 3,5-diamino-4-phenylazopyrazole toward a variety of reagents is reported. Several new 3,5-diaminopyrazole derivatives as well as amino derivatives of fused pyrazoles have been prepared.ZusammenfassungEs wird über das Verhalten von 3,5-Diamino-4-phenylazopyrazol gegenüber verschiedenen Agentien berichtet. Es wurden sowohl einige neue 3,5-Diaminooyrazol-Derivate als auch einige Aminoderivate von kondensierten Pyrazolen dargestellt.

STUDIES WITH POLYFUNCTIONALLY SUBSTITUTED HETEROAROMATICS: NEW ROUTES FOR SYNTHESIS OF BENZOAZINES

Abstract Pyridazine (I) reacts with dimethyl acetylenedicarboxylate and with N-phenyl-maleimide yielding phthalazine (II) and pyrrolophthalazine (III), respectively. Pyridine IV reacts with benzylidene malononitrile to give compound VI. Compounds VIa–c could be successfully converted into the isoquinolines XIa–c on treatment with acrylonitrile. In contrast to the behavior of arylidene malononitrile, compound IV react with N-phenylmaleimide to yield the pyrroloisoquinoline XIII. Similarly, the reaction of compound IV with each of tetracyanoethylene and dimethyl acetylenedicarboxylate gave compounds XIV and XV respectively.

Studies on Alkyl Heterocyclic Aromatic Compounds: New Routes for the Synthesis of Polyazanaphthalenes

Several new polyfunctionally substituted polyazanaphthalene derivatives could be synthesized via condensing readily obtainable polyfunctional nitriles with substituted alkyl heteroaromatic derivatives and reacting the latter derivatives with electrophilic reagents