a practical and green method for the synthesis of 5h-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (csa) under solvent-free conditions at 100 °c is described. the significant features of this pro...

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 green and efficient one pot, three component protocol for synthesis of naphthopyranopyrimidines by cyclocondensation of β-naphthol, aldehyde, and 6-amino-1,3-dimethyluracil using L-proline as a beneficial catalyst with high catalytic activity under solvent-free conditions at 100 °C is described. In this study, several types of aromatic aldehyde, containing electron-withdrawing groups as well ...

A simple and efficient method for the synthesis of quinolines and polycyclic quinolines using Li+ modified nanoporous Na+-montmorillonite is described. This new nanocatalyst proceeds via Friedlander annulation under solvent-free conditions. It describes our observations about a trend of catalytic activity of Lithium cation in nanoporous Na+-montmorillonite. In this study, several types of 1,3-d...

mesoporous photocatalysts of ceo2/sba-15 are prepared by two methods of direct synthesis as solvent-usage and solvent-free methods. in solvent-usage method, ceo2/sba-15 is synthesized in acidic media. while, in solvent-free method, ceo2/sba-15, has been prepared through the novel path of directly grind cerium salt into the as-prepared samples of sba-15 occluded with template. this method enable...

the present study aimed to use a method for the synthesis of some 3, 4-dihydropyrimidin-2-(1h) - ones/thiones. the study tried to answer the question whether this reaction can be performed without solvent and with new catalyst or not. to find answer to the question, we described a novel protocol for the efficient synthesis of 3, 4-dihydropyrimidin-2-(1h)-one derivatives using aromatic aldehyde,...

silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.

A simple, clean, and environmentally benign three-component process for the synthesis of 2-amino-4Hchromenes using [mim]Cl, as an efficient catalyst under solvent-free conditions are described. A wide range of aromatic aldehydes easily undergoes condensations with 1-naphthol and malononitrile under solvent-free conditions to afford the desired products of good purity in excellent yields. Taking...

Mesoporous photocatalysts of CeO2/SBA-15 are prepared by two methods of direct synthesis as solvent-usage and solvent-free methods. In solvent-usage method, CeO2/SBA-15 is synthesized in acidic media. While, in solvent-free method, CeO2/SBA-15, has been prepared through the novel path of directly grind cerium salt into the as-prepared samples of SBA-15 occluded ...