A microwave-assisted solid-phase synthesis of heteroannulated 1,3-oxazin-6-ones has been developed. Significant rate enhancement was observed for all steps carried out under microwave irradiation, and the overall reaction time was dramatically shortened when compared to the conventional procedures. A representative set of 20 bi- and tricyclic heteroannulated 1,3-oxazin-6-ones was prepared. Key steps in the synthesis are (i) five-member heterocycle formation, (ii) acylation of amine, and (iii) ring closure to give the heteroannulated 1,3-oxazin-6-one.
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http://dx.doi.org/10.1021/cc800193r | DOI Listing |
Molecules
September 2024
Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo 11711, Egypt.
2-Chloropyridine-3-carbonitrile derivative was utilized as a key precursor to build a series of linear and angular annulated pyridines linked to a 6-hydroxy-4,7-dimethoxybenzofuran moiety. Reaction of substrate with various hydrazines afforded pyrazolo[3,4-]pyridines. Treatment of substrate with 1,3-,-binucleophiles including 3-amino-1,2,4-triazole, 5-amino-1-tetrazole, 3-amino-6-methyl-1,2,4-triazin-5(4)-one and 2-aminobenzimidazole produced the novel angular pyrido[3,2-][1,2,4]triazolo[4,3-]pyrimidine, pyrido[3,2-][1,2,4]tetrazolo[1,5-]pyrimidine, pyrido[3',2':5,6] pyrimido[2,1-][1,2,4]triazine and benzo[4,5]imidazo[1,2-]pyrido[3,2-]pyrimidine, respectively.
View Article and Find Full Text PDFMolecules
May 2024
Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo 11711, Egypt.
The goal of this study was directed to synthesize a novel class of annulated compounds containing difuro[3,2-:3',2'-]chromene. Friedländer condensation of -aminoacetyl derivative was performed with some active methylene ketones, namely, 1,3-cyclohexanediones, pyrazolones, 1,3-thiazolidinones and barbituric acids, furnished furochromenofuroquinolines (,), furochromenofuropyrazolopyridines (-), furochromenofurothiazolopyridines (,) and furochromenofuropyridopyrimidines (, ), respectively. Also, condensation of substrate with 5-amine-3-methyl-1-pyrazole and 6-amino-1,3-dimethyluracil, as cyclic enamines, resulted in polyfused systems and , respectively.
View Article and Find Full Text PDFChem Commun (Camb)
April 2023
Shenzhen Research Institute of Hunan University, Shenzhen, 518000, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
While the heteroannulation of arylene diimides serves as a powerful approach for designing new π-functional materials, most of the heteroannulated arylene diimides are constructed based on π-extension at their -areas or -directions. Herein, based on a -region O-annulation strategy, a novel O-doped polyaromatic hydrocarbon O-ADA was successfully prepared, showing not only ambipolar charge transport with improved charge mobilities, but also much red-shifted NIR absorption profiles and thus yielding enhanced photothermal conversion efficiencies upon light irradiation as compared to its parent ADA compound.
View Article and Find Full Text PDFOrg Lett
December 2022
Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, Kolkata 700032, India.
Palladium(0)-catalyzed reactions between allenamides or and aryl iodides/bromides / provide an easy access to δ-carbolines or benzofuro[3,2-]pyridines . The reaction constitutes a fast intermolecular assembly that takes place in one pot, and the choice of the phosphine ligand is critical for success. A plausible reaction mechanism is proposed.
View Article and Find Full Text PDFPharmaceuticals (Basel)
March 2022
Center of Scientific Excellence for Influenza Viruses, National Research Centre, Giza 12622, Egypt.
There is an urgent need to develop and synthesize new anti-influenza drugs with activity against different strains, resistance to mutations, and suitability for various populations. Herein, we tested in vitro and in vivo the antiviral activity of new 1,2,3-triazole glycosides incorporating benzimidazole, benzooxazole, or benzotriazole cores synthesized by using a click approach. The Cu-catalyzation strategy consisted of 1,3-dipolar cycloaddition of the azidoalkyl derivative of the respective heterocyclic and different glycosyl acetylenes with five or six carbon sugar moieties.
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