The focus of this paper was to identify a cheaper solvent from among diesel fuel, kerosene, sulfolane or a mixture of sulfolane and cyclohexanol for the preparation of cyanuric acid heterocyclization of urea. To obtain a higher yield, the effects of catalyst (sodium, ammonium, calcium and zinc salts) and temperature (160 degrees C to 220 degrees C) on the trimerization of urea were also careful...

The reaction of cyanoacetylhydrazine 1 with furan-2-aldehyde 2 gives the hydrazide-hydrazone derivative 3. The latter compound undergoes a series of heterocyclization reactions to give new heterocyclic compounds. The antitumor evaluation of the newly synthesized products against three cancer cell lines, namely breast adenocarcinoma (MCF-7), nonsmall cell lung cancer (NCI-H460) and CNS cancer (S...

The reaction of phenylhydrazoethyl acetoacetate (1) with cyanoacetyl hydrazine (2) in an oil bath in the presence of ammonium acetate gave the pyridazine derivative 4. However, carrying the same reaction but in ethanolic/Et3N gave the pyrazole derivative 5. Compounds 4 and 5 were used in a series of heterocyclization reactions to afford products that showed anti-tumor activities towards three c...

The selective construction of a diverse array of five-membered aromatic heterocycles from common starting materials is an attractive and challenging task. We report here that 5-alkylthio-pyrroles, 4-alkylthiocarbonyl-pyrroles and 2-alkylthio-4-tosyl-furans can be prepared, selectively, in a single operation using the readily available α-formyl ketene dithioacetals as common precursors, through ...

In the presence of 1 mol% of a copper(II) catalyst and air, a readily available N-acetyl-N-thioacylguanidine undergoes a one-pot benzylic oxidation–oxidative heterocyclization sequence to give the 3-amino5-acyl-1,2,4-thiadiazole core of polycarpathiamines A (2) and B (3) and thus facilitating the first synthesis of both natural products. This methodology offers a straightforward alternative to ...

In this paper we report the synthesis of new compounds based on the pyrazole and isoxazole framework fused to a cycloalkene unit, and bearing as a substituent the 1-piperidinyl group as new examples of potential antipsychotic molecules. The general synthesis involves the acylation of a chloro-substituted cyclic ketone with a 1-substituted piperidine-4-carboxylate derivative, followed by heteroc...

The reaction of cyanoacetyl hydrazine (1) with the -haloketones 2a-2c in 1,4-dioxane afforded the hydrazidehydrazone derivatives 3a-3c. The latter products were used in a series of heterocyclization to give 1,3,4-oxadiazine, 1,2,4triazine and pyrazole derivatives. All compounds synthesized through this work are new products and their antitumor evaluation towards three human tumor cell lines rep...

The reaction of 5,5-dimethylcyclohexane-1,3-dione with various heteroarylaldehydes afforded the corresponding heteroaryl substituted xanthene derivatives 1(a-f). The reaction proceeds via the initial Knoevenagel, subsequent Michael, and final heterocyclization reactions using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst in aqueous media. The synthesized heteroaryl substituted xanthenes 1...

A highly efficient and versatile synthetic approach to the synthesis of annelated quinazoline derivatives viz. 3,4,9,10a-tetraazaphenanthrenes 5 – 7, thiazolidinylquinazoline 9, 2,4,9,10a-tetraazaphenanthrene 11, quinazolino[4,3-b]quinazolin-8-one 12 and imidazoquinazolines 14a,b, 15. Also, a variety of pyrazolylquinazolines 19 – 21, pyrimidinylquinazolines 22a,b were obtained via a sequence of...