Kamal Usef Sadek

Cerium (IV) Ammonium Nitrate (CAN) Catalyzed One-pot Synthesis of 2-Arylbenzothiazoles

A one-pot synthesis of 2-arylbenzothiazoles from the reaction of 2-amino-thiophenol and aromatic aldehydes catalysed by cerium (IV) ammonium nitrate (CAN) is reported.

Regioselectivity in the multicomponent reaction of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal under controlled microwave heating

Summary The multicomponent reaction of 5-aminopyrazole derivatives with cyclic 1,3-dicarbonyl compounds and dimethylformamide dimethylacetal (DMFDMA) in DMF at 150 °C under controlled microwave heating afforded regioselectively 8,9-dihydropyrazolo[1,5-a]quinazolin-6(7H)-ones 6 rather than the corresponding dihydropyrazolo[5,1-b]quinazolin-8(5H)-ones 4.

Green and Highly Efficient Synthesis of 2-Arylbenzothiazoles Using Glycerol without Catalyst at Ambient Temperature

A one-pot and clean synthesis of 2-arylbenzothiazoles via the ambient temperature reaction of 2-aminothiophenols and aromatic aldehydes without catalyst in glycerol as a green solvent has been reported.

A NOVEL SYNTHESIS OF BENZO[g]IMIDAZO[1,2-a]PYRIDINES: THE REACTIVITY OF ARYLIDINE-1H-BENZIMIDAZOLE-2- ACETONITRILE WITH ELECTRON POOR OLEFINS AND DIMETHYLACETYLENE DICARBOXYLATE UNDER MICROWAVE IRRADIATION

Arylidine-1 H-benzimidazole-2-acetonitriles reacted with ß-nitrostyrene, acrylo-nitrile and dimethylacetylene dicarboxylate under microwave irradiation to afford benzo[g]imidazo[l,2-a]pyridines in high yields. Introduction Benzimidazo[l,2-a]pyridines have received increasing interest over the past years (1) owing to their biological activities. For example, many of their derivatives are known as antifungal, anthelmintic and local anesthetic agents (2). The organic synthesis under microwave healing technique and without solvent is now receiving considrable interest (3,4). It is worth to mention that this technique offers several advantages : solvents are usually toxic, expensive, difficult to remove in the case of aprotic dipolar solvents with high boiling points and are environments air polluting agents. Results and Discussion As a part of our program aiming to synthesis polyfunctionally substituted condensed heterocycles via simple routes and unexpensive starting materials (5,6), we report here a novel synthesis of benzo[g]imidazo[l,2-a]pyridines by reaction of arylidine-1Hbenzimidazole-2-acetonitriles la,b with ß-nitrostyrene, acrylonitrile and dimethylacetylene

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.

Synthesis and Spectroscopic Properties of New Azo Dyes Derived from 3-Ethylthio-5-cyanomethyl-4-phenyl-1,2,4-triazole

New 1,2,4-triazole colorants were obtained, in high yields, by coupling 3-ethylthio-5-cyanomethyl-4-phenyl-1,2,4-triazole (1) with diazotized aniline derivatives 2, 4 and 6. The azo dyes prepared in this work may exist in three tautomeric forms. We found that the tautomerism is influenced mainly by the nature of substituent at the para position of the aniline coupling component. This tautomerisation was observed in the NMR spectra of the dyes. The dyes were characterized by IR, 1H-NMR, 13C-NMR and MS spectroscopic techniques.

A CONVENIENT ONE POT SYNTHESIS OF PYRIDO[2,3-d]- PYRIMIDINES AND PYRIMIDO[2,3-c]PYRIMIDINES (N5-DEAZAPETRINS)

A convenient one pot synthesis of pyrido[2,3-d]pyrimidines and pyrimido[2,3-c]pyrimidines via reaction of 6-amino-2-oxo-4-thioxotetrahydropyrimidine 1 with cinnamonitrile derivatives 2 has been reported.

Novel synthesis of pyrazolo[5,1-c]-1,2,4-triazoles, imidazo[1,2-b]pyrazoles, and [1,2,4]-triazolo[4,3-a]benzimidazoles. Reaction of nitrite imines with amino- and oxo-substituted diazoles

The behaviour of several amino- and hydroxy-diazoles towards nitrite imines and hydrazonoyl halides is reported. The results indicate that nitrite imines can add to the double bonds in amino- and hydroxy-heterocyclic derivatives. However, the nature of the end product is dependent on the nitrite imine, the substituent on the heterocyclic ring, and the type of heterocyclic ring.

Reactions with heterocyclic diazonium salts: novel synthesis of pyrazolo[4,3-c]pyridazines and of pyrazolo[4,3-c]pyrazoles

Diazotised 4-amino-1,5-dimethyl-2-phenylpyrazol-3(2H)-one (1) coupled with active methylene nitriles to yield the corresponding cyanohydrazones (3a–c) and (11). Compounds (3a–c) afforded the 4-(3-aminopyrazol-4-ylidenehydrazino)-1,5-dimethyl-2-phenylpyrazol-3(2H)-ones (5a–c) on treatment with hydrazine hydrate, and cyclised to give the pyrazolo[4,3-c]pyridazines (7a–c) on treatment with ethanolic hydrochloric acid. The hydrazone (11) cyclised to give the pyridazin-6-one derivative (12) when boiled under reflux in ethanol. Diazotised pyrazolone (1) coupled with 3-chloropentane-2,4-dione and with ethyl 2-chloro-3-oxobutanoate to yield the pyrazolo[4,3-c]pyrazole derivatives (9a and b).

Reactions with the Arylhydrazones of some α-Cyanoketones

Abstract The N-methylarylhydrazones of mesoxalodinitrile (3) and of ethyl cyanoglyoxalate (7) could be prepared via methylation of the corresponding phenylhydrazones 4 and 6 respectively. The hydrazones 3 and 8 reacted with hydrazine hydrate to yield the amidra-zone 1 and the hydrazide 2 b. The behavior of compounds 1 and 2 a, b towards a variety of reagents is reported. A variety of new α-arylhydrazononitriles were synthesised.