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...

bifunctional acidic ionic liquids, having both h-imidazolium and -so3h groups as cation moieties (h-bfails) and cf3so3- as anion, were synthesized in high yields. these h-bfails showed significant hydrophilic properties, lower acidity and higher thermal stability relative to common ionic liquids, due to their unique structures. the (propyl or butyl-3-sulfonic) imidazolium trifluoromethane sulfo...

an efficient, simple and convenient route is described for the synthesis of biscoumarin (3,3'-(arylmethylene) bis (4-hydroxy-2h-chromen-2-one)) by using of recyclable catalyst tio2@ksf. in this method, we synthesis biscoumarin derivatives via 3multi-component reactions (3mcrs) of two equivalent 4-hydroxycoumarin with one equivalent of aromatic aldehydes using 20 mg nano tio2@ksf as homogen...

The fate and impact of elemental mercury in closed bacterial cultures were examined. The quantity of elemental mercury oxidized by bacteria ranged from small amounts for Pseudomonas aeruginosa, P. fluorescens, Escherichia coli, and Citrobacter to essentially all of the added elemental mercury for Bacillus subtilis and B. megaterium. The percentage of the total mercury in the system associated w...

in this research, (carboxy-3-oxopropylamino)-3-propylsilylcellulose (copapsc) as an organocatalyst, has been synthesized by grafting of succinic anhydride on the nh2-modified cellulose (cellulose functionalized with 3- aminopropyltriethoxysilane). the –co2h group-functionalized cellulose (copapsc) is used as a catalyst for the synthesis of coumarin derivatives from the reaction of phenolic subs...

Mercury is a naturally occurring metal, one of the most toxic metals within the food chain and has a number of uses in the Irish health care sector. This paper reports on a mercury survey in Ireland with the purpose to present a picture of mercury use in health settings. The findings show 50% of health settings free of all mercury medical equipment. Mercury spills occur within 30% of health set...

Mercury is a pervasive environmental contaminant and a well-documented immunosuppressor. However, little is known about the effects of mercury contamination on health of free-living vertebrate populations. The South River in Virginia, USA was heavily contaminated with industrial mercury from 1929 to 1950, and recent studies have documented high levels of circulating mercury in riparian songbird...

the acetylation of various alcohols and phenols was performed successfully using acetic anhydride in the presence of citric acid coated magnetite nanoparticles as catalyst under solvent-free condition and at 45 °c. the catalyst showed high thermal stability and was recovered and reused at least 5 times without any considerable loss of activity. the present process is environmentally benign and ...

d-tartaric acid is successfully used as a green and efficient catalyst for the synthesis of 3,4-dihydropyrimidin-2(1h)-ones under solvent-free conditions. the developed method has many advantages, including devoid of harmful catalyst and solvents, high yield and easily work-up.