Ramadan Ahmed Mekheimer

Solar thermochemical reactions: four-component synthesis of polyhydroquinoline derivatives induced by solar thermal energy

The synthesis of polyhydroquinoline derivatives via a four-component unsymmetric Hantzsch reaction induced by solar thermal energy is reported. The process proved to be simple, environmentally friendly, economic and high yielding.

Novel 1,2,4-triazolo[1,5-a]pyridines and their fused ring systems attenuate oxidative stress and prolong lifespan of Caenorhabiditis elegans.

In this paper we report the synthesis of some novel 1,2,4-triazolo[1,5-a]pyridine and azolotriazolopyridine ring systems. The products were screened for various types of activity like antibacterial, antifungal, and antioxidative activity. Compound 13 was found to pose an antioxidative activity. In addition, this compound was found to extend the life span of Caenorhabiditis elegans under standard laboratory conditions and reduces both heat and chemical induced oxidative stress in C. elegans in a dose-dependent manner. Furthermore, treatment of worms with compound 13 was found to significantly attenuate the formation of advanced glycation end products and malondialdehyde in a dose-dependent manner.

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.

Green chemistry: a facile synthesis of polyfunctionally substituted thieno[3,4-c]pyridinones and thieno[3,4-d]pyridazinones under neat reaction conditions.

A facile, solvent free, ecofriendly approach for the synthesis of pyridine-2,6-diones 4a-d, pyridazinone derivatives 8a-c and thienoazines 6 and 9 is herein described employing neat reaction conditions under both microwave and ultrasound irradiations. This solventless methodology is environmentally benign as it completely eliminates the use of solvent from the reaction procedure.

Green, three component highly efficient synthesis of 2-amino-5,6,7,8-tetrahydro-4-H-chromen-3-carbonitriles in water at ambient temperature

Abstract A three component synthesis of 2-amino-5,6,7,8-tetrahydro-4-H-chromen-3-carbonitriles using aldehydes, malononitrile, and dimedone in water at ambient temperature was 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

Simple, Three-Component, Highly Efficient Green Synthesis of Thiazolo[3,2-a]pyridine Derivatives Under Neat Conditions

Abstract Green, highly efficient, three-component syntheses of thiazolo-[3,2-a]pyridine derivatives via reaction of malononitrile, aromatic aldehydes, and 2-mercaptoacetic acid with a catalytic amount of piperidine without solvent with molar ratios of 2:2:1.2 and 2:2.2:1, respectively, has been reported.

FUSED QUINOLINE HETEROCYCLES. II. FIRST SYNTHESIS OF 1,2,3,4,5,6-HEXAAZAACEANTHRYLENES AND 5,7,8,10a,11-PENTAAZABENZO[a]-FLUORENES

The new tetracyclic ring systems 5-alkyl-1,5-dihydro-1,2,3,4,5,6-hexaazaaceanthrylenes 5a–d were synthesized by diazotization of 4-alkylamino-3-amino-1H-pyrazolo[4,3-c]quinolines 4a–d. The 4-arylamino-3-diazo-1H-pyrazolo-[4,3-c]- quinolines 6e–h, which were prepared by diazotisation of the corresponding amines 4e–h, readily formed the novel tetracyclic ring system ethyl 6-arylamino-10-methyl-5,7,8,10a,11-pentaazabenzo[a]fluorene-9-carboxylates 8e–h, when treated with ethyl acetoacetate.