Decatungstodivanadogermanic acid (H6GeW10V2O40.22H2O) was used as a green heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones from one-pot three-component cyclocondensation reaction of a β-ketoester, an aldehyde and urea/thiourea under solvent-free conditions is reported. This method provides an efficient and much improved modification of the original Biginelli reaction...

An efficient synthesis route to 1,4-dihydropyrimidine derivatives from reaction of divergent aldehydes with ethylacetoacetate and urea under solvent-free conditions by ZnO nanoparticles as a relative in expansive, eco-friendly, easy available, non-volatile, non-explosion, thermally robust, recyclable and easy to handle catalyst at 90°C with excellent yields is described. Unenhanced reaction tim...

An efficient synthesis route to 1,4-dihydropyrimidine derivatives from reaction of divergent aldehydes with ethylacetoacetate and urea under solvent-free conditions by ZnO nanoparticles as a relative in expansive, eco-friendly, easy available, non-volatile, non-explosion, thermally robust, recyclable and easy to handle catalyst at 90°C with excellent yields is described. Unenhanced reaction tim...

Decatungstodivanadogermanic acid (H6GeW10V2O40.22H2O) was used as a green heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones from one-pot three-component cyclocondensation reaction of a β-ketoester, an aldehyde and urea/thiourea under solvent-free conditions is reported. This method provides an efficient and much improved modification of the original Biginelli reaction...

Silica boron sulfonic acid [SiO2–B(OSO3H)3] as an inexpensive, reusable, and Lewis and Brønsted acid catalyst was successfully synthesized, and used for the one-pot three-components synthesis of biologically active substituted Hantzsch 1,4-dihydropyridine derivatives  in the absence of solvent at 90ºC. Silica boron sulfonic acid is attractive and efficient, because it plays in two role as a Lew...

A facile and efficient synthesis of bis(indolyl)methanes derivatives (3a-u) was reported via a condensation reaction of aldehydes and indole in the presence of by silica-supported-3-(triethoxysilyl) propane-1-ammonium chloride catalysis under solvent free conditions. We studied the reaction in different conditions and optimized. The use of just 0.02 g of (silica gel-ammonium salt) is sufficient...

In this research, a Brønsted acidic ionic liquid namely N1,N1,N2,N2-tetramethyl-N1,N2-bis(sulfo)ethane-1,2-diaminium chloride {[TMBSED][Cl]2} was employed as a highly efficient catalyst for the solvent-free production of some nitrogen- and oxygen-containing heterocyclic compounds including: (i) polyhydroquinolines (from arylaldehydes, dimedone, β-ketoesters and ammonium acetate), (ii) 3,4-dihyd...

A green and convenient method for the synthesis of 14-aryl-14H-dibenzo[a,i]xanthene-8,13-diones and spiro[dibenzo[a,i]-xanthene-14,3'-indoline]-2',8,13-triones in the presence of a catalytic amount of cellulose sulfuric acid (CSA) as an efficient biopolymer-based catalyst under solvent-free conditions at 100 °C is described. The condensation reactions of β-naphtol, 2-hydroxynaphthalene-1,4-dion...

An efficient synthesis of Methyl 2-[2-(alkylimino)-4-oxo-3-phenyl-1,3-thiazolan-5-yliden]acetate derivatives via simple three-component reaction and one-pot reactions between isoquinoline, dimethyl acetylenedicarboxylate and N-phenylthiourea under solvent-free conditions without using any additional catalyst, is described. The mild reaction conditions and good yields and exhibit the synthetic a...

The reaction of 2-naphthol and also para-substituted phenols with glyoxal in presence of choline chloride: 2 ZnCl2 [ChCl: 2ZnCl2], a deep eutectic solvent (DES), as a green catalyst was studied. The amount of catalyst, solvent type, temperature, and time on the yield of reaction were investigated. It was found that the optimal condition included 10% mol ratio of catalyst (mol percentage of DES ...