نتایج جستجو برای: Solvent –free

تعداد نتایج: 560809  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1392

a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...

Journal: :iranian chemical communication 0
abbas amini manesh payame noor university, hamedan ardeshir khazaei faculty of chemistry, bu-ali sina university, p.o. box 651783868, hamedan, iran maedeh gohari department of chemistry, payame noor university, 19395-4697 tehran, i. r. of iran mahdieh chegeni department of chemistry, faculty of science, ayatollah ozma boroujerdi university, boroujerd, iran shahnaz saednia young researchers & elites club, toyserkan branch, islamic azad university, toyserkan, iran

methoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of 1,3-dichloro-5,5-dimethyl hydantoin [dcdmh] and poly n,n′-dibromo-n-ethyl naphthyl-2,7-disulfonamide [pbns] as catalysts at room temperature and under solvent-free conditions. our experiments show that primary and secondary alcohols can be smoothly converted into the corresponding mom...

Journal: :physical chemistry and electrochemistry 0

2-amino-substituted ketones react with α-methylene ketones under solvent-free conditions at 90 °c in thepresence of a catalytic amount of zirconium dodecylphosphonate to create the corresponding quinolinesin excellent yields. this procedure recommends numerous advantages such as easy work-up, use of mild,reusable and safe catalyst, short reaction timeand high yields. the new compounds have been...

Journal: :international journal of nano dimension 0
a. yahyazadeh department of chemistry, university of guilan, p.o. box 41335-1914, rasht, iran. v. azimi department of chemistry, university of guilan, p.o. box 41335-1914, rasht, iran

copper (ii) phthalocyanine and 2,9,16,23 tetrakis nitro copper (ii) phthalocyaninehas been synthesized respectively from phthalonitrile and 4-nitro phthalonitrile under solvent-free condition using two different catalystsovernanodimensionalzeolites. 4-nitro phthalonitrile synthesized from phthalimide in three steps. the newly prepared compounds have been characterized by ir, uv-vis, 1hnmr and m...

Journal: :iranian journal of science and technology (sciences) 2012
h. sharghi

highly active cu (ii) complex with 1,4-dihydroxy anthraquinone as a cheap and accessable ligand could be used as a catalyst for the preparation of structurally different propargylamines from a one-pot, three-component reaction of terminal alkynes, aldehydes, and secondary amines with high yields under solvent-free conditions. the 1,4-dihydroxy anthraquinone is a very efficient cu(ii) scavenger ...

Journal: :chemistry of solid materials 2013
a. yahyazadeh v. azimi

copper (ii) phthalocyanine and 2, 9, 16, 23 tetrakis nitro copper (ii) phthalocyanine has been synthesized respectively from phthalonitrile and 4-nitro phthalonitrile under solvent-free condition using two different catalysts over nanodimensional zeolites. 4-nitro phthalonitrile synthesized from phthaimide in three steps. the newly prepared compounds have been characterized by ir, uv-vis,1h nm...

Journal: :iranian chemical communication 2016
bagher mohammadi maryam rahmani

this work described a simple and efficient synthesis of dialkyl 3-(alkylamino)-1-aryl-1h-pyrazole-4,5-dicarboxylates via a three component reaction between arylhydrazine, alkylisocyanid and dialkylacetylenedicarboxylates in the presence of phenylisocyanate and α-fe2o3 nanoparticles. eco friendly, solvent-free conditions, excellent yields, and short reaction times, inexpensive and readily availa...

Journal: :iranian journal of catalysis 0
mona hosseini-sarvari department of chemistry, shiraz university, shiraz 71454, i.r. iran. sepideh najafvand-derikvandi department of chemistry, shiraz university, shiraz 71454, i.r. iran.

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...

Journal: :iranian journal of catalysis 2011
hossein naeimi abdol hamid raesi mohsen moradian

the use of methanesulfonic acid as a brønsted acid for direct ortho-acylation of phenols and naphthols proves to be a convenient, more general and direct route to various hydroxyaryl ketones. the route is regioselective, leading to ortho c-acylated products in satisfactory to high yields in most cases. the solvent free reactions described below exhibited environmentally benign in terms of faste...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید