friedel–crafts synthesis of triarylmethanes over 3-methyl-1-sulfonicacid imidazolium tetrachloroaluminate under green conditions:in this work, friedel–crafts (fc) alkylation of various arenes with aromatic aldehydes catalyzed by 3-methyl-1-sulfonic acid imidazoliumtetrachloroaluminate {[msim]alcl4}, as a green catalyst, to prepare triarylmethanes (tams) has been carried out. some aromatic aldeh...

3,4-dihydropyrimidin-2(1h)-thiones were synthesized in the presence of ag nanoparticle/melamine sulfonic acid (msa) supported on silica gel. the reaction was carried out at 110 oc for 20 min under solvent free conditions. in all cases, the three component reaction proceeded smoothly to give the corresponding 3,4-dihydropyrimidin-2(1h)-thiones in moderate to good yield. we have found the best co...

A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...

In this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1H)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using Al-MCM-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. The advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.

Silica supported phosphorus pentoxide (P2O5·SiO2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. Simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.

Efficient and one-pot synthesis of 1,8-dioxo-octahydroxanthenes was described by Knoevenagel condensation, Michael addition and cyclodehydration of dimedone. This reaction was carried out through condensation of dimedone and various aromatic aldehydes in the presence of task-specific Brønsted acidic ionic liquid under solvent free conditions. The catalyst could be recycled five times without si...

Molybdate sulfuric acid (MSA) has been prepared and used as catalyst for the Biginelli synthesis of some quinazolinones/thiones under solvent-free conditions. The catalyst loading is low and it shows recyclability. This method has advantages such as avoidance of the organic solvents, high yield of pure products, short reaction times and operational simplicity.

Poly(4-vinylpyridine)-supported copper iodide nanoparticles is reported as a new, green and recyclable catalyst for the synthesis of aryl-14H-dibenzo [a-o] xanthenes under solvent-free conditions. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any loss of their efficiency.

A simple and efficient procedure has been developed for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones derivatives under solvent-free conditions. This method uses the condensation of isatoic anhydride, aldehydes, and amines in the presence of a catalytic amount Sulfonated Porous Carbon (SPC). One of the important advantages of the new method is that the SPC could be recycled and reused.

A new, facile, cost effective, and eco-friendly protocol is reported for the synthesis of 2,3-dihydroquinazoline-4-(1H)-ones exploring tannic acid as a novel, inexpensive, andbiodegradable catalyst. A variety of dihydroquinazolins were prepared from aromatic aldehydesand anthranilamide using catalytic amount of tannic acid under solvent free conditions.Operational simplicity, high yield, and hi...