scholarly journals Tandem grinding reactions involving aldol condensation and Michael addition in sequence for synthesis of 3,4,5-trisubstituted isoxazoles

RSC Advances ◽  
2019 ◽  
Vol 9 (48) ◽  
pp. 27883-27887
Author(s):  
Xiao-Mu Hu ◽  
Hai Dong ◽  
Yue-Dan Li ◽  
Ping Huang ◽  
Zhuang Tian ◽  
...  

3,4,5-Trisubstituted isoxazoles were prepared, using a tandem grinding strategy, from aromatic aldehydes, 3,5-dimethyl-4-nitroisoxazole and activated methylene compounds in the presence of pyrrolidine and Et3N with high yields and efficiency.

2019 ◽  
Vol 9 (4-A) ◽  
pp. 280-289
Author(s):  
SEKAR SILAMBU SILAMBARASAN ◽  
A. Jamal Abdul Nasser

A highly efficient and environmentally benign for the synthesis a of 2-amino-7-hydroxy-4-aryl-4H-chromene-3-carbonitrile derivatives (4a-n) in good to high yields (90%-97%) by one-pot three-component Michael addition reaction of malononitrile, aromatic aldehydes and resorcinol under reflux condition was developed in aqueous medium. Single crystal X-ray studies show that 4h crystallizes in the formula C22H15Cl2N2O2, Mr=410.26, Monoclinic, Space group P2(1)/c, a=12.753(9)Å, b=6.665(4)Å, c=24.050(14) Å, β=102.95(3)A° and 4i C16H10Cl2N2O2, Mr=333.16, Triclinic, Space group P-1, a=6.271(3)Å, b=18.697(5)Å, c =13.794(7) Å,  β =94.269(17)A°. The structure of the products were further confirmed by 1H NMR, 13C NMR, IR and Mass spectrum. Keywords: Benzopyrans, malononitrile, resorcinol, Michael addition, water mediated synthesis, single crystal XRD


2018 ◽  
Vol 21 (4) ◽  
pp. 298-301 ◽  
Author(s):  
Ghasem Marandi

Aim and Objective: The reaction of cyclohexylisocyanide and 2-aminopyridine-3- carboxylic acid in the presence of benzaldehyde derivatives in ethanol led to 3-(cyclohexylamino)-2- arylimidazo[1,2-a]pyridine-8-carboxylic acids in high yields. In a three component condensation reaction, isocyanide reacts with 2-aminopyridine-3-carboxylic acid and aromatic aldehydes without any prior activation. Material and Methods: The synthesized products have stable structures which have been characterized by IR, 1H, 13C and Mass spectroscopy as well as CHN-O analysis. Results: In continuation of our attempts to develop simple one-pot routes for the synthesis of 3- (cyclohexylamino)-2-arylimidazo[1,2-a]pyridine-8-carboxylic acids, aromatic aldehydes with divers substituted show a high performance. Conclusion: In conclusion, this study introduces the art of combinatorial chemistry using a simple one-pot procedure for the synthesis of new materials which are interesting compounds in medicinal and biological sciences.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Kobra Nikoofar ◽  
Fatemeh Shahriyari

AbstractA simple, straightforward, and ultrasound-promoted method for the preparation of some highly functionalized tetrahydropyridines reported via pseudo five-component reaction of (hetero)aromatic aldehydes, different anilines, and alkyl acetoacetates in the presence of [N-CH2CO2H-3-pic]+HSO4−, as a novel ionic liquid, in green aqueous medium. The IL was synthesized utilizing simple and easily-handled substrates and characterized by FT-IR, 1H NMR, 13C NMR, GC-MASS, FESEM, EDX, and TGA/DTG techniques. The procedure contains some highlighted aspects which are: (a) performing the MCR in the presence of aqua and sonic waves, as two main important and environmentally benign indexes in green and economic chemistry, (b) high yields of products within short reaction times, (c) convenient work-up procedure, (d) preparing the new IL via simple substrates and procedure.


Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1589-1592 ◽  
Author(s):  
Abolfazl Olyaei ◽  
Mahnaz Saraei ◽  
Reyhaneh Khoeiniha

A high-yielding cyclocondensation of 4-hydroxycoumarin, phenylglyoxal monohydrate, and heteroarylamines proceeds without catalysis, which gives novel functionalized furo[3,2-c]coumarins and heteroarylamino alkylation of coumarin products in acetonitrile under reflux, is reported for the first time. This tandem process involves sequentially an aldol condensation, Michael addition, a ring closure, and dehydration reaction.


RSC Advances ◽  
2014 ◽  
Vol 4 (100) ◽  
pp. 57016-57025 ◽  
Author(s):  
Eethamukkala Ubba ◽  
Fazlur-Rahman Nawaz Khan ◽  
Euh Duck Jeong ◽  
Eun Hyuk Chung

Microwave supported, water intervened, nano crystalline TiO2 catalyzed synthesis of 3-(1,5-dioxo-1,5-diphenylpentan-3-yl)quinolin-2(1H)-ones, is described.


RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30166-30169 ◽  
Author(s):  
James O. Guevara-Pulido ◽  
José M. Andrés ◽  
Deisy P. Ávila ◽  
Rafael Pedrosa

Enantioenriched seven membered rings have been prepared in high yields and stereoselectivities by intramolecular Michael addition of functionalized enals catalyzed by Jorgensen–Hayashi catalyst.


2021 ◽  
Vol 25 ◽  
Author(s):  
Neda Reihani ◽  
Hamzeh Kiyani

: An efficient synthesis of 4-arylidene-3-alkylisoxazole-5(4H)-ones has been implemented via the three-component cyclocondensation of aryl(heteroaryl)aldehydes with hydroxylamine hydrochloride and β-ketoesters. The potassium 2,5-dioxoimidazolidin-1-ide has been introduced as the new organocatalyst to facilitate of this heterocyclization. In the current process, three starting materials, including substituted benzaldehydes/heterocyclic aromatic aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/propyl acetoacetate/butyryl acetoacetate have been successfully used for the synthesize of the number of substituted isoxazole-5(4H)-ones in good to high yields in ethylene glycol as a green reaction medium at 80 ºC. The low catalyst loading is also a main advantage over the some reported catalysts.


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