A facile and highly efficient protocol was applied successfully to synthesize 4H-pyrimido[2,1,b]benzimiazoles and 4H-pyrimido[2,1,b]benzothiazoles through one-pot three-component cyclocondensation reactions of 2-aminobenzimidazole or 2-aminobenzothiazole with dimedone and aromatic aldehydes in the presence of guanidinium chloride under solvent-free conditions. The reactions us...

Reusable silica supported perchloric acid and potassium bisulphate have been prepared and explored as green catalysts for thiocyanation of aromatic compounds under conventional and solvent free microwave assisted conditions. The microwave assisted protocol exhibited remarkable rate accelerations and offered selective thiocyanation of aromatic and hetero aromatic compounds in good yields. Reacti...

     Cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120 °C to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-H-benzo[a]xanthen-11-one derivatives in high yields. Also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensu...

Ni2+ supported on hydroxyapatite-core@shell γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp-Ni2+) was found to be a useful catalyst for the synthesis of benzimidazole derivatives from o-phenylenediamine and aldehydes under solvent and solvent-free conditions at 80 °C. This reaction affords the corresponding benzimidazole derivatives compared with the classical reactions this method consistently gives a high...

The oxidations of organic compounds by permanganate under solvent free conditions have been studied. Thiols and primary aromatic amines undergo oxidative coupling reactions to give disulfides and diazenes, respectively, sulfides are oxidized to sulfones, primary and secondary alcohols are converted to aldehydes and ketones, 1,4-diols and cyclic ethers give lactones and arenes are oxidized to th...

Lithium perchlorate is a Lewis acid catalyst which activates a large number of organic reactions providing high yields with enhanced reaction rates. Moreover, it makes some of the reactions possible to proceed under solvent-free conditions which is an important aspect for the development of green chemistry. This paper canvasses the chemical literature on lithium perchlorate as a catalyst for or...

An efficient method for synthesis of 1Acetal diethyl-1H-indole-3-carbaldehyde by combinaison of 1H-indole-3-carbaldehyde and bromoacetal diethyl using Natural phosphate doped with K2CO3 (NP/K2CO3) is described .The reactions promoted by microwave irradiation are advantageous in many ways because of short reaction time, and solvent free reaction conditions . Several reactions of synthetic import...

The new novel series of 2-amino-5-phenyl thiazole derivatives were occurred in the reaction between thiourea and various substituted ketones. The reactions were carried out in the microwave oven under solvent free condition. The completion of the reactions was checked by TLC. The structures of the compounds were characterized by FT-IR, 1 H and 13 C NMR and elemental analysis. Synthesized compou...

a highly efficient and simple method for the preparation of α,α´-bis(arylidene)cycloalkanones under solvent-free conditions has been developed. the crossed-aldol condensation of cycloalkanones (1 eq.) with arylaldehydes (2 eq.) in the presence of 2.5 mol% of ionic liquid 1,3-disulfonic acid imidazolium hydrogen sulfate {[dsim]hso4} afforded the title compounds in high yields and short reaction ...