Rafat M. Shaker

ONE-POT SYNTHESIS OF NOVEL 1,1′- AND 1,4-BRIDGED BIS-THIAZOLIDINONE DERIVATIVES AND THEIR ANTIMICROBIAL ACTIVITY

Abstract Several bis-thiazolidinone derivatives 6a-e, 9a,b and 13a,b have been synthesized and have discussed the IR, 1H-NMR, 13C-NMR and mass spectra of these compounds. Compounds 6a-e have also been screened in vitro for antibacterial activities.

Synthesis and Biological Activities of Novel 1,4-Bridged Bis-1,2,4-Triazoles, Bis-1,3,4-Thiadiazoles and Bis-1,3,4-Oxadiazoles

Abstract The terephthalic acid hydrazide(1) reacted with phenyl/benzyl isothiocyanate2a,bto yield the corresponding bis-thiosemicarbazides4a,b,viaacid hydrolysis of the intermediate 3whereas cyclization of4gave the bis-1,2,4-triazoles 5,6and bis-1,3,4-thiadiazoles7,8. Similarly, compound 1reacted with phenyl isocyanate9to give the bis-semicarbazide10, which was cyclized to the bis-oxadiazole 11and/or bis-1,2,4-triazole12in POClti3and NaOH respectively.

SYNTHESIS AND TRANSFORMATION OF 2-THIOXOPYRIMIDO [4,5-d]PYRIMIDINES

Abstract Synthesis of bicyclic system pyrimido[4,5-d]pyrimidines and its S-mono- and unsymmetrical S.S′-di-substituted deivatives are described.

SYNTHESIS OF 2-THIOXOPYRIDO[2,3-d]PY RIMIDINE-4- ONES AND 1,4-BRIDGED BIS-2-THIOXO-1,2,3,4-TETRAHYDRO-5-PYRIMIDINE CARBOXYLIC ACID ETHYL ESTER DERIVATIVES

Abstract The synthesis and structural characterization of 2-thioxopyrido[2,3-d]pynmidinethiones 5,9,12 and 4,4′-(1,4-phenylene)-di-(2-thioxo-1,2,3,4-tetrahydropyrimidines) 16-22 are described.

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

On the Reaction between 1-Aza-1,3-dienes and Push-Pull Olefins of the Acyloxymethylidene-malononitrile Type

Summary. The reaction between push-pull olefins of the acyloxymethylidene-malononitrile type and α, β-unsaturated hydrazones affords selectively 5-alkyl-2-cyano-6-(N′,N′-dimethylhydrazono)-hexa-2,4-dienenitriles. No [4+2]-cycloaddition products were detected. The structure elucidation of the obtained compounds and possible reaction mechanisms are discussed.

Synthesis of 4,4′-(1,4-Phenylene)di-pyridine and-pyrimidine Derivatives†

The preparation and structural characterization of4,4′-(1,4-phenylene)di-pyridine and -pyrimidine derivativesare described.

HETEROCYCLES SYNTHESIS THROUGH REACTIONS OF NUCLEOPHILES WITH ACRYLONITRILES, PART 5, SYNTHESIS OF SEVERAL NEW THIAZOLE AND THIAZOLO[2,3-a]PYRIDINE DERIVATIVES

Abstract Several new thiazole and thiazolo[2,3-a]pyridine derivatives were prepared by reaction of the thiazolin-4-one derivatives 2 (synthesised from α-cyano-2-ethylacetanilide and thioglycollic acid) with acrylonitriles 1a-h.

Synthesis and Reactivity of 3-Alkylthio-5-cyanomethyl-4-phenyl-1,2,4-triazoles

Phenyl isothiocyanate reacts with 2-cyanoacetohydrazide (1) to yield the corresponding 1-cyanoacetyl-4-phenyl-thiosemicarbazide (3), via acid hydrolysis of the intermediate 2 whereas cyclization of 3 gave the 1,2,4-triazoles 4, 1,3,4-thiadiazoles 7 and 1,3,4-thiadiazine-5-ones 9; compound 4a was reacted with phenyl isothiocyanate, dicyandiamide, sulfanylacetic acid and benzaldehyde to afford 11, 13, 14 and 15, respectively.