an improved, simple, and facile synthesis of 3,4-dihydropyrimidin-2(1h)-ones by employing three-component, one-pot condensation reaction of β-keto ester, aromatic aldehydes, and urea or n-methylurea using lacl3/clch2cooh as an inexpensive and green chemistry catalyst system under solvent-free conditions described. compared with the classicalbiginelli reaction conditions, this method has the adv...

Freshly prepared ZnO nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. The conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid reactants and hydroxylamine hydrochloride with ZnO nanoparticles under solvent-free condition. The procedure was carried out und...

Palladium supported on nickel ferrite (Pd/NiF(2)O(4)) was found to be a highly active catalyst for the Suzuki coupling reaction between various aryl halides and arylboronic acids. The reaction gave excellent yields (70-98%) under ligand free conditions in a 1:1 DMF/H(2)O solvent mixture, in short reaction times (10-60 min). The catalyst could be recovered easily by applying an external magnetic...

Transesterification is one of the most popular methods to decrease the viscosity of vegetable oils to produce biodiesel. It is the reaction of vegetable oil/ fats with an alcohol to give fatty acid alkyl esters in the presence of a catalyst with glycerol as by product. A catalyst is used to increase the rate of reaction and yield. The reaction is very much affected by the free fatty acids conte...

Succinimidinium hydrogensulfate ([H-Suc]HSO4), as a new and stable derivative of succinimide, is easily prepared by the reaction of succinimide with neat sulfuric acid. This ionic liquid can be used as an efficient catalyst for the acetylation of alcohols, phenols, thiols and amines at room temperature under mild and solvent free conditions. All the products are separated and identified using d...

a facile and efficient method for the preparation of 1,1-diacetates of aldehydes is improved. the acidified kaolin with sulfuric acid (2 % w/w) catalyzed 1,1-diacetates formation from aldehydes in solvent-free conditions. both aromatic and aliphatic aldehydes gave high yields (85-95 %) of the corresponding 1, 1-diacetates. advantages of this method are the use of inexpensive and selective catal...

A new catalyst was prepared by promoting fly ash with hydrogen peroxide. The catalytic activity of H2O2 promoted fly ash (HPFA) was evaluated by synthesis 5(4H)-oxazolone and imidazolone derivatives under solvent free conditions. The possible mechanisms of synthesis reactions were also suggested. These proposed methods benefit in terms of low-cost catalyst, high yields, ease of workup, survival...

A series of N-heteroaryl formamides were efficiently synthesized from heteroarylamines and formic acid using Al2O3 nanoparticles as a heterogeneous catalyst under solvent-free conditions. The smaller size of Al2O3 nanoparticles with a higher surface to volume ratio has a promising catalytic activity, resulting in a short reaction times and high reaction yields under mild reaction conditions. Th...

The catalytic cracking of methane over nickel gauze is proposed as an attractive alternative for the production of CO-free hydrogen. The catalyst deactivates due to intensive coke deposition. Therefore, the reactor was operated periodically with the reaction followed by the catalyst regeneration by burning of coke in oxidative atmosphere. The optimal reaction performance was found to consist of...

A water soluble, Bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. Cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally fri...