نتایج جستجو برای: pot procedure
تعداد نتایج: 629235 فیلتر نتایج به سال:
An efficient route to substituted 1-aryl-1H-indazoles has been developed and optimized. The method involved the preparation of arylhydrazones from acetophenone or benzaldehyde substituted by fluorine at C2 and nitro at C5, followed by deprotonation and nucleophilic aromatic substitution (SNAr) ring closure in 45-90%. Modification of this procedure to a one-pot domino process was successful in t...
Freshly prepared ZnO nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. The conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid reactants and hydroxylamine hydrochloride with ZnO nanoparticles under solvent-free condition. The procedure was carried out und...
2-Methylpyridinum p-toluenesulfonate ([2-MPy][p-TSA]) as a novel room temperature ionic liquidwas synthesized and evaluated as a recoverable catalyst for the one-pot synthesis ofhexahydroquinoline-3-carboxamide derivatives by four-component reaction of arylaldehydes,dimedone, acetoacetanilide and ammonium acetate in high to excellent yield in ethanol at 50 oC.The [2-MPy]...
BACKGROUND The classical Strecker reaction is one of the simplest and most economical methods for the synthesis of racemic α-aminonitriles (precursor of α-amino acids) and pharmacologically useful compounds. RESULTS Indium powder in water is shown to act as a very efficient catalyst for one-pot, three-component synthesis of α-aminonitriles from diverse amines, aldehydes and TMSCN. This genera...
determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...
An operationally simple one-pot, two-step procedure for the desymmetrization of benzils is herein described. This consists in the chemoselective cross-benzoin reaction of symmetrical benzils with aromatic aldehydes catalyzed by the methyl sulfinyl (dimsyl) anion, followed by microwave-assisted oxidation of the resulting benzoylated benzoins with nitrate, avoiding the costly isolation procedure....
Diverse meso-aminophenyl-, hydroxyphenyl-, and phenyl-substituted heptamethine cyanine dyes were prepared by a modified Suzuki--Miyaura method in good yields. In addition, direct Suzuki coupling of Vilsmeier--Haack reagent extends the procedure to the synthesis of otherwise difficult cyanine dyes containing multiple heteroatoms in the indolium ring. The new compounds possess excellent spectral ...
Abstract A novel basic ionic liquid based on imidazolium cation is designed, synthesized and successfully used as a catalyst for the one-pot synthesis of 4-Oxo-6-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile derivatives. The remarkable features of this new catalyst are its ethyleneoxy bridge which participates in dissolving organic compound in the ionic liquid and its strong base co...
An efficient procedure to obtain the new compound 1a from ethyl acetoacetate (2a), NBS and N,N′-diethylthiourea (4a) was reported. In comparison with the traditional method to synthesize its analogues, this efficient, catalyst-free, and one-pot synthetic method is facile. The work-up procedure is easy and gives the pure target compound under milder reaction conditions in a relatively high yield...
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