Search

Abstract: A simple and facile synthesis of 12-aryl-12H-indeno[1,2-b]naphtho[3,2-e]pyran-5,11,13-trione derivatives was accomplished via the one-pot condensation of 2-hydroxynaphthalene-1,4-dione, aldehydes, and 2H-indene-1,3-dione at 100°C under solvent-free conditions in the presence of the solid acid catalyst, poly(4-vinylpyridinium) hydrogensulfate. This method has the advantages of high yields, clean reactions, simple methodology, and short reaction times. The catalyst could be recycled and reused four times without significant loss of activity. The structures of the novel compounds were confirmed by IR, 1H NMR, and elemental analysis. [Copyright &y& Elsevier]

Abstract: Wells-Dawson heteropolyacids (H6P2W18O62·24H2O) were used as catalysts in the Hantzsch-like multicomponent condensation reaction with 3-formylchromones as aldehyde component, a β-ketoester and ammonium acetate, under solvent-free conditions at 80°C. Although the desired products were obtained, functionalized pyridines were the main reaction product and became the alternative route to dihydropyridine ring formation. Based on the proposed mechanisms for the formation of each of the obtained products, the multicomponent reaction was modified to afford only the functionalized pyridines (60–99%). Our procedure represents a clean alternative for the synthesis of several highly functionalized pyridines. [Copyright &y& Elsevier]

Abstract: We described herein the use of glycerol as solvent in the catalyst-free synthesis of benzodiazepines and benzimidazoles. This simple and efficient method furnishes the corresponding 1-H-1,5-benzodiazepines and 1,2-disubstituted benzimidazoles in good yields by the condensation of o-phenylenediamine with several ketones and aldehydes, respectively. In addition, glycerol can be easily re-utilized for further condensation reactions up to four times without lost of activity. [Copyright &y& Elsevier]

Abstract: Baker’s yeast catalyzed one-pot three-component cyclocondensation of aryl aldehydes, malononitrile, and β-dicarbonyls in organic medium has been carried out to obtain polyfunctionalized 4H-pyrans. The reaction has been carried out at room temperature in organic solvent, dimethylacetamide and the products obtained in good to moderate yields with simple work up procedure. [Copyright &y& Elsevier]

Abstract: An efficient one-pot method has been developed for the synthesis of α-oxycarbanilinophosphonates via a one-pot reaction of an aldehyde with diethyl phosphite in the presence of magnesium oxide followed by reaction with an isocyanate under solvent-free conditions using ultrasonic irradiation. This method is simple, rapid and good yielding. [Copyright &y& Elsevier]

Abstract: The cyclocondensation of 2-aminothiophenol and aldehydes has been carried out in dichloromethane using bakers’ yeast as a catalyst for obtaining 2-aryl/heteryl benzothiazoles in good yields. [Copyright &y& Elsevier]