نتایج جستجو برای: simple reaction time

تعداد نتایج: 2561403  

A practical and new method for the synthesis oxindole substituted pyrrolo[2,3-d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °C was described. The reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3-d]pyrimidines in good to excellent yields. All reactions performed effic...

Farzaneh Maliji Rahman Hosseinzadeh, Zahra Lasemi

Montmorillonite KSF has been used as an effective and non-toxic heterogeneous catalyst for one-pot synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition of sodium azide with a wide variety of nitriles. The reaction afforded high yields of the desired products in a short reaction time under mild reaction conditions. The catalyst can be recovered by simple filtration and reuse...

In this research, a green, operationally simple, highly efficient and facile cascade Biginelli reaction using various aromatic aldehydes, ethyl acetoacetate, and urea/thiourea has been developed. First, the ionic liquid was prepared from the reaction of 1-methyl-2-pyrolidone with methane sulfonic acid. Then, this ionic liquid was applied as an acidic catalyst in the synthesis of dihydropyrimidi...

A simple, efficient, and high yielding one-pot protocol has been developed for the synthesis of 4H-benzo[b]pyrans scaffolds installing a three-component tandem Knoevenagel-cyclocondensation reaction of an aldehyde, malononitrile and dimedone using guanidinium chloride as polyfunctional organocatalyst under solvent-free conditions in high to excellent yields. Various aromatic aldehydes were util...

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...

Sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) with a pore size of 6 nm catalyzed three component coupling of aromatic aldehydes, urea and ethyl acetoacetate to afford the corresponding dihydropyrimidinones under solvent free condition. This new protocol for Biginelli reaction has important advantages such as green synthesis, short reaction time, easy isolation and high yields of ...

Farzaneh Maliji Rahman Hosseinzadeh, Zahra Lasemi

Montmorillonite KSF has been used as an effective and non-toxic heterogeneous catalyst for one-pot synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition of sodium azide with a wide variety of nitriles. The reaction afforded high yields of the desired products in a short reaction time under mild reaction conditions. The catalyst can be recovered by simple filtration and reuse...

Ali Reza Badiei Ghodsi Mohammadi Ziarani, Mahbobeh Haddadpour Yeganeh Khaniania

Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the Hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. SBA-P...

2014
Michael Kennefick Anthony Carlsen Anthony N. Carlsen Romeo Chua Tony Carlsen

The process of movement execution can be separated into two sections; the foreperiod and the response time. The foreperiod represents the time between the warning signal (WS) and the presentation of the imperative “go” signal, and the response time incorporates both the reaction time (RT) and the movement time (Schmidt & Lee, 2011). Transcranial magnetic stimulation (TMS) was used to probe cort...

Journal: :iranian journal of catalysis 2014
esmayeel abbaspour-gilandeh seyyedeh cobra azimi

the ionic liquid li(ohch2ch2nh2)(cf3oac) was found to efficiently catalyze the three-component reaction between different enols, aldehydes, and malononitrile , leading to rapid synthesis of 2-amino-4h-chromene derivatives in fairly high yields. the catalyst is easily prepared, highly stable, simple to handle and recycled for several times without significant loss of activity. the method is simp...

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