Organic chemistry
Asadollah Farhadi; Milad Ramyar; Mohammad Ali Takassi
Volume 6, Issue 3, pp. 218-324, Serial No. 20 , July 2018, , Pages 266-270
Abstract
A protocol for the synthesis of 1,4-dihydropyridines (Hantzsch type-products) was developed by means of a three-component condensation of an aldehyde, a β-dicarbonyl compound, ammonium acetate and nano Al2O3/KF as catalyst. This reaction was carried out under different conditions including i) solvent-free ...
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A protocol for the synthesis of 1,4-dihydropyridines (Hantzsch type-products) was developed by means of a three-component condensation of an aldehyde, a β-dicarbonyl compound, ammonium acetate and nano Al2O3/KF as catalyst. This reaction was carried out under different conditions including i) solvent-free ii) and reflux in different solvents. In all conditions, the desired products were obtained in high yields after relatively short reaction times. Nevertheless, the reactions proceed faster and in higher yields when they were carried out in ethanol. Compared to the classical Hantzsch reaction conditions and previously reported protocols, this protocol has the advantages of consistently excellent yields and short reaction times. After the reaction, the catalyst could be recovered easily.
Organic chemistry
Mohammad Reza Poor Heravi; Naheed Morsalie
Volume 6, Issue 1, pp. 1-108, Serial No. 18 , January 2018, , Pages 87-96
Abstract
Highly substituted 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized by four-component reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and various phenylhydrazine, using nickel ferrite as a recyclable nanocatalyst by a grinding method under solvent-free and thermal conditions. ...
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Highly substituted 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized by four-component reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and various phenylhydrazine, using nickel ferrite as a recyclable nanocatalyst by a grinding method under solvent-free and thermal conditions. The reaction has the advantages of good yields, less pollution, ease of separation of the desired products, and of being environment friendly. A possible mechanism for this reaction was proposed. Highly substituted 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized by four-component reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and various phenylhydrazine, using nickel ferrite as a recyclable nanocatalyst by a grinding method under solvent-free and thermal conditions. The reaction has the advantages of good yields, less pollution, ease of separation of the desired products, and of being environment friendly. A possible mechanism for this reaction was proposed.
Organic chemistry
Radineh Motamedi; Sara Sobhani; Farshid Barani
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 338-344
Abstract
Some Chromeno[4,3-b]quinoline derivatives were synthesized in a tricomponents one-pot reaction of 1,3-cyclohexadione arylaldehydes and 4-aminocoumarin under Microwave irradiation in the solventless system by using a heteropolyacid catalyst ,H3[PW12O40] in 80-95% yields and high rates. The shorter reaction ...
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Some Chromeno[4,3-b]quinoline derivatives were synthesized in a tricomponents one-pot reaction of 1,3-cyclohexadione arylaldehydes and 4-aminocoumarin under Microwave irradiation in the solventless system by using a heteropolyacid catalyst ,H3[PW12O40] in 80-95% yields and high rates. The shorter reaction times, one-pot, good yields, simple work-up procedure and environmentally friendly conditions are the main advantages of this method compared to the two step method. Heteropolyacid is separated by filtration and the products were purified by flash column chromatography. The reactions were monitored by TLC and subsequent work-up afforded a single compound by TLC in each case. The product was identified by its 1H NMR, mass and IR spectra, which were compared to those reported previously.
Organic chemistry
Abdolkarim Zare; Mahshad Rezaei; Alireza Hasaninejad
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 94-101
Abstract
A highly efficient and simple method for the preparation of α,α´-bis(arylidene)cycloalkanones under solvent-free conditions has been developed. The crossed-aldol condensation of cycloalkanones (1 eq.) with arylaldehydes (2 eq.) in the presence of 2.5 mol% of ionic liquid 1,3-disulfonic ...
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A highly efficient and simple method for the preparation of α,α´-bis(arylidene)cycloalkanones under solvent-free conditions has been developed. The crossed-aldol condensation of cycloalkanones (1 eq.) with arylaldehydes (2 eq.) in the presence of 2.5 mol% of ionic liquid 1,3-disulfonic acid imidazolium hydrogen sulfate {[Dsim]HSO4} afforded the title compounds in high yields and short reaction times. The catalyst has dual-functions and it is so because of possessing three acidic functional groups with different Brønsted acidic and basic sites. High catalytic activity and low loading of the catalyst can be attributed to its dual-functions. The promising points for the presented protocol are simple and clean reaction profile, efficiency, generality, low catalyst loading, high yields, performing the reaction in solvent-free media without side reactions, non-toxicity as well as low cost of the catalyst, and good compliance with the green chemistry protocols, which makes it an attractive procedure for the synthesis of α,α´-bis(arylidene)cycloalkanones as an important class of organic compounds.