One-pot strategy to synthesize seven–membered 1,4-diazepine heterocyclic scaffolds assisted by zinc oxide nanoparticles as heterogeneous catalytic support system

Abstract

The present paper elicits the zinc oxide nanoparticles-assisted synthesis of a new series of seven-membered 1,4-diazepine heterocyclic compounds as potent lead scaffolds. Structures of synthesized compounds were corroborated using spectroanalytical techniques viz, FT-IR, 1H, 13C NMR, Mass, and elemental analysis. Also, Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Energy dispersive x-ray analysis (EDAX), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FT-IR) were used to establish the structure and morphology of the synthesized nanocatalyst. The clean workup procedure, high to excellent yields, relatively short reaction times, and high atom economy are the incredible advantages associated with the protocol.

Zinc Oxide Nanoparticles as Efficient Heterogeneous Catalyst for Synthesis of Bio‐active Heterocyclic Compounds

“…[178] The high-yielding onepot synthesis of pyrazolo-o- [4,3 : 5,6]pyrido[2,3-d] pyrimidinedione using 3-methyl-pyrazolone,(135) 1, 3-dimethyl barbituric acid (136), aryl aldehydes (90), and ammonium acetate was associated with ZnO-NPs (Scheme 26). For the synthesis of pyrido [2,3-d]derivatives (137) in the proposed mechanism, initially, ZnO-NPs shows interaction with the carbonyl oxygen of aldehyde (90) and activated the aldehyde for nucleophilic attack of 3-methyl-pyrazolone (135) for the formation of compound (138). In second step, the reaction carried out between 1, 3-dimethyl barbituric acid (136), and ammonium acetate and form compound (139) with the removal of water.…”

“…The ZnO-NPs are shows both Lewis-acid and Lewis-basic sites which can be found on the surface of zinc oxide. [137] As useful intermediates in the synthesis of fusion hetero-diazepine molecules bringing triazole oxadiazole, oxazine, and furano-nuclei, several kinds of 1, 4-azepine derivatives also find usage as colors for acrylic fibers. 35), Meldrum's acid (36), and isocyanide derivatives (37) in the presence ZnO-NPs.…”

“…Recently, G. Pandey and co‐workers reported synthesis of new seven‐member series of 1, 4‐diazepine heterocyclic compounds ( 32 and 34 ) catalyzed by ZnO‐NPs (Scheme 6). The ZnO‐NPs are shows both Lewis‐acid and Lewis‐basic sites which can be found on the surface of zinc oxide [137] . As useful intermediates in the synthesis of fusion hetero‐diazepine molecules bringing triazole oxadiazole, oxazine, and furano‐nuclei, several kinds of 1, 4‐azepine derivatives also find usage as colors for acrylic fibers.…”