توضیحات
ABSTRACT
Potassium fluoride/Holloysite nonotube (KF/HNTs) acts an active hetrogeneos base catalyst for Biginelli reaction. Here we have describe An efficient one-pot synthesis of 3,4- dihydropyrimidine-2(1H)-one via a three-component reaction of aldehyde, urea, and β-ketoester in the presence of a catalytic amount of (KF/HNTs). The experimental results showed that the KF/HNTs had high catalytic activity and it can be recycled without significant loss of activity. This protocols exhibit advantages such as excellent yield, easy work-up and eco-friendly conditions.
INTRODUCTION
The Biginelli reaction involving a multicomponent condensation of aldehyde, urea, and β- ketoester, is the mostefficient method for the synthesis of 3,4-dihydropyrmidin-2-(1H)-one. Much effort was directed toward developing highly efficient Biginelli reaction owing to the exhibition of a wide range of biological activities in dihydropyrimidinones such as antitumor , antibacterial , such as calcium-channel blocker , alpha-la-antagonism , antihypertensive agents and neuropeptide Y antagonism . Traditional homogeneous systems suffer from problems such as low catalyst recovery, complicated product separation and harsh reaction conditions in most cases. To overcome these drawbacks, several methods have been developed to prepare recoverable heterogeneous catalysts, using various supports, for the Biginelli reaction . Recently, Biginelli reaction has been conducted under basic conditions. This involves the use of PPh3, under solvent free conditions , t-BuOK at 70°C , chiral primary amines , ammonium carbonate in water and nano ZnO as a structure base catalyst . We suggest a new protocol for the synthesis of DHPs by use of supported reagents. The major advantage of supported reagent is the reusability of the catalyst that makes the process inexpensive . Furthermore, it also contributes towards the area of “Green Chemistry”. Our interest in organic reactions carried out under heterogeneousconditions prompted us to investigate the utility of solid bases in carbon–carbon bondforming reactions. Among the salts with potentially basic properties potassium fluoride (KF) is more general owing to its cheapness and availability. A lot of supports have been introduced for increasing the basicity of KF such as KF/ZnO, KF/Ca–Mg–Al, KF/CaO–Fe3O4, KF/Cp, KF/celite, KF/zeolite, and KF/LDH mainly applied for organic production. Although, a majority of the abovementioned solid bases are effective in organic transformations, they suffer from some drawbacks such as low basicity, use of expensive solid supports and tedious preparation steps.
Year: 2017
Publisher : 4 International Confranc on Racent Innovations in Chemistry and Chamistry Engineering
By : Mercedeh Ghanei , Mohammad A. Khalilzadeh, Mohammah Mahmoodi Hashemi, Issa Yavary
File Information: English Language/ 9 Page / size: 288 KB
سال : 1396
ناشر : چهارمین کنفرانس بین المللی نوآوری های اخیر در شیمی و مهندسی شیمی
کاری از : مرسده غنی، محمد علی خلیل زاده ، محمحا محمودی هاشمی ، عیسی یاوری
اطلاعات فایل : زبان انگلیسی / 9 صفحه / حجم : KB 288
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