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Microwave-Assisted Synthesis and Functionalization of Six-Membered Oxygen Heterocycles
Published in Banik Bimal Krishna, Bandyopadhyay Debasish, Advances in Microwave Chemistry, 2018
Neha Batra, Rahul Panwar, Ramendra Pratap, Mahendra Nath
Pyrans are six-membered oxygen heterocycles with a molecular formula C5H6O. These molecules occupy a unique place in pharmaceutical chemistry as they possess anticancer and antihypertensive activities [164].
Nano-cell-OBF2: an efficient and cheap catalyst for one-pot synthesis of pyrano[4,3-b]pyrans under mild and green condition
Published in Inorganic and Nano-Metal Chemistry, 2019
Saeed Mousavi Khatat, Bahareh Sadeghi, Maryam Ghasemi
In this study, nano-cell-OBF2 catalysis was successfully prepared and characterized, using FTIR, TGA/DTG and SEM/EDXs. Although evidently it efficiently catalyzed, a one pot three-component reaction of aldehydes, malononitrile and 4-hydroxy-6-methyl-2H-pyran-2-one, resulting in the formation of pyrano [4,3-b] pyrans. Some of the advantages of this method include faster reactions, simple development, providing desirable yields, collecting and reusing for multiple times without considerable decline in its activity. In these set of reactions, no hazardous organic solvent was involved. Hence, this process highly conforms to green chemistry system and can be classified as an environmentally friendly reaction.
Facile route for the synthesis and cytotoxic effect of 2-amino-4H-benzo[b]pyran derivatives in aqueous media using copper oxide nanoparticles decorated on cellulose nanocrystals as heterogeneous catalyst
Published in Inorganic and Nano-Metal Chemistry, 2019
Clarina Thanaraj, G.R. Priya Dharsini, Neela Ananthan, Rama Velladurai
Pyrans, an heterocyclic compound constitute the core fragment in variety of natural products, have a broad spectrum of biological properties such as anticoagulants, spasmolytics, diuretic, anticancer and antianaphylactic activities.[1] Benzopyrans as pharmaceutical ingredients used as cognitive enhancers for the treatment of neurodegenerative diseases, including Huntington’s disease, Alzheimer’s disease, AIDS-associated dementia and Down’s syndrome and also used as pigments and photoactive materials.[2] The significant importance of 2-amino-4H-benzo[b]pyrans scaffold in medicinal field draws chemist considerable interest to synthesis these compounds employing the catalysts such as (s)-proline,[3] MgO,[4] nanosized ZnO,[5] LiBr,[6] silica NPs,[7] silica gel-supported polyphosphoric acid,[8] [bmim]OH,[9] infrared irradiation,[10] inorganic-organic hybrid magnetic nanocatalyst,[11] meglumine,[12] hydroxyapatite,[13] per-6-amino-β-cyclodextrin,[14] urea,[15] potassium phthalimide,[16] CoFe2O4 nanoparticles,[17] DABCO,[18] salicyldimine-schiff’s complex of copper (II),[19] CuFe2O4 nanoparticles,[20] lactose,[21] Fe3O4@SiO2-imid-PMAn,[22] poly(4-vinylpyridine)-supported copper iodide nanoparticle,[23] ethylenediamine diacetate,[24] sodium alginate,[25]N,N-dimethylbenzylamine,[26] gold nanoparticles supported on thiol functionalized reduced graphene oxide,[27] glutamic acid,[28] potassium hydrogen phthalate,[29] Fe3O4@GA@lsinglass core/shell magnetic nanoparticles,[30] ammonium hydroxide or ultrasonic irradiation,[31] pyridine-4-carboxylic acid-functionalized Fe3O4 nanoparticles,[32] organocatalyst.[33]