Mamdouh A. M. Afifi

Bio: Mamdouh A. M. Afifi is an academic researcher from Cairo University. The author has contributed to research in topics: Moiety & Bicyclic molecule. The author has an hindex of 4, co-authored 5 publications receiving 42 citations.

Reactions of hydrazidoyl halides: synthesis of imidazo[2,1-b]thiazole, thiazolo[2,3-c]-as-triazole and heterocyclic enaminonitriles

Abstract: Arylazo derivatives of imidazo[2,1-b]thiazoles could be obtained via reaction of hydrazidoyl halides with 2-aminothiazole. Thiazolo[2,3-c]-as-triazole and heterocyclic enaminonitriles were obtained in good yields from hydrazidoyl halides and triethylamine and from malonitrile, respectively. Pyrazolo[3,4-d]pyrimidines and pyrazolo[3,4-d]pyridazines were obtained via reaction of heterocyclic enaminonitriles with formic acid and hydrazine hydrate, respectively. The structures of the products were assigned and confirmed on the basis of their elemental analyses and spectral data.

Reactions with Hydrazonoyl Halides 611: Synthesis of 2,3-Dihydro-1,3,4-Thiadiazoles

Abstract: 2-[1,2-Diaza-3-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))prop-2-enylidene]-3-phenyl-5-substituted 1,3,4-thiadiazolines and 2-{[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]cyanomethylene}-3-phenyl-5-substitu- ted 1,3,4-thiadiazolines were synthesized from hydrazonoyl halides and 4-{-2-aza-2-[(methylthiothioxomethyl)amino]vinyl}-2,3-dimethyl-1-phenyl-3-pyrazoin-5-one and 2-[4-(2,3-dimethyl-5-oxo-1-phenyl-3-pyrazolin-4-yl)-1,3-thiazol-2-yl]ethane-nitrile, respectively. All synthesize compounds were elucidated by elemental analysis, spectra, and alternative synthesis routes, whenever possible.

Synthesis of Some New Thiazoles and Pyrazolo[1,5-a]pyrimidines Containing an Antipyrine Moiety.

Abstract: Ethyl 2-{2-[4-(2,3-dimethyl-5-oxo-1-phenyl-3-(pyrazolin-4-yl)]-2-cyano-1-(phenylamino)vinylthio}-acetate, 2-[4-(2,3-dimethyl-5-oxo-1-phenyl-(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]2-(4-oxo-3-phenyl-(1,3-thiazoilidin-2-ylidene))ethanenitrile, 2-[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]-2-(4-methyl-3-phenyl(1,3-thiazolin-2-ylidene))ethanenitrile, 2-(5-acetyl-4-methyl-3-phenyl(1,3-thiazolin-2-ylidene))-2-[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]ethanenitrile, and ethyl 2-(cyano(4-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)thiazol-2-yl)methylene)-2,3-dihydro-4-methyl-3-phenylthiazole-5-carboxylate were synthesized by treatment of 2-(4-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)thiazol-2-yl)-3-mercapto-3-(phenylamino)-acrylonitrile with appropriate halo ketones or halo esters. Also, 4-{2-[5,7-dimethyl-2-(phenylamino)(7a-hydropyrazolo[1,5-a]pyrimidin-3-yl](1,-thiazol-4-yl)}-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one derivatives were ...

The Chemistry of Heterocyclic Hydrazonoyl Halides

Abstract: Publisher Summary Hydrazonoyl halides have emerged as an important class of intermediates, particularly for the synthesis of heterocyclic compounds. This chapter discusses the synthesis, properties, and reactions of Hydrazonoyl Halides. The mechanisms of some of the reactions and the structures of some of the products are outlined. Direct halogenation of arylhydrazone derivatives of both aliphatic and aromatic aldehydes with the appropriate halogen in glacial acetic acid is an excellent method for the synthesis of the corresponding hydrazonoyl halides. Halides are also obtained by refluxing with N- bromosuccinimide in dry carbon tetrachloride. Furthermore, bromination of aldehyde N-heteroarylhydrazones in acetic acid in the presence of sodium acetate sometimes leads to intramolecular cyclization of the initial hydrazonoyl bromides to yield the corresponding cyclized products. However, from the foregoing survey of heterocyclic hydrazonoyl halides, it appears that the main emphasis has been restricted to both their preparation and use as intermediates for further synthesis. Large areas of their chemistry, particularly regarding their physical and biological properties, remain to be developed.

Four-component domino strategy for the combinatorial synthesis of novel 1,4-dihydropyrano[2,3-c]pyrazol-6-amines

Abstract: An efficient one-pot four-component domino protocol for the combinatorial synthesis of novel 1,4-dihydropyrano[2,3-c]pyrazol-6-amines has been achieved. This transformation presumably occurs via cyclization–Knoevenagel condensation–Michael addition–tautomerism–intramolecular O-cyclization–elimination sequence of reactions. The significant features of this reaction include expedient one-pot process, short reaction time, no column chromatographic purification, excellent yield, and readily available starting materials.