A series of isoflavone functionalized 3,4‐dihydro‐1,3‐oxazine hybrids was synthesized in good to excellent yields through a Mannich‐type condensation cyclization reaction of 6‐chloro‐7‐hydroxy‐3‐(2‐methoxy‐phenyl)‐chromen‐4‐one or 6‐chloro‐7‐hydroxy‐3‐(2‐methoxy‐phenyl)‐chromene‐4‐thione with formaldehyde and primary amines. After spectroscopic characterization, these newly prepared hybrids were evaluated for their antibacterial activities against two of each Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains. Among the screened compounds, dihydro[1,3]oxazine‐fused 4‐thionoisoflavones(9 band9 c) exhibited potent inhibitory activity against all the tested bacterial species. Moreover, compound 9 b possessed most promising antibacterial activity against P. aeruginosa and B. subtiliswith MIC 16 μg/mL and S. aureusand E. coliwith MIC 32 μg/mL. Further, 9 bdemonstrated better efficacy (MIC=16 μg/mL) than the standard drug ampicillin (MIC=32 μg/mL) against P. aeruginosaand it also found to be equipotent (MIC=16 μg/mL) as ampicillin against B. subtilis. Considering the disk diffusion and synergistic studies, 9 bemerged asmost active compound showing potent activity against all the tested bacterial strains. In addition, no significant hemolysis or cytotoxicity was observed towards human embryonic kidney (HEK293)cells as well as Galleria mellonellalarvae (in vivo). Hence, compound 9 bhas potential to be further explored alone and in combination with ampicillin as a next generation antibacterial agent.

A series of benzenesulfonamide‐appended [1,2,3]‐triazole hybrids was synthesized by using [3 + 2] cycloaddition of primary, secondary, and tertiary sulfonamide azides with various phenoxymethylacetylenes under click reaction conditions. After structural characterization, the compounds were subjected to in‐silico absorption, distribution, metabolism, excretion and toxicity (ADMET) screening to evaluate their drug‐likeness and other pharmacokinetic parameters. Furthermore, their in vitro antiplasmodial potential was assessed against Plasmodium falciparum (3D7) strain, and some of the synthesized compounds displayed promising antimalarial potency. On cytotoxicity evaluation using MTT cell viability assay, the most active candidate N‐(4,6‐dimethylpyridin‐2‐yl)‐4‐(4‐(4‐nitrophenoxy)methyl)‐1H‐[1,2,3]‐triazol‐1‐yl)benzenesulfonamide (14; IC50 6.2 μg/mL) demonstrated CC50 7.5 μg/mL against human hepatocarcinoma (HUH‐7) cells.

: Dihydro[1,3]oxazines are an important class of heterocyclic compounds having a wide range of biological and material properties. Medicinally, they possess diverse pharmacological activities such as bactericidal, fungicidal, microbiocidal, antitumor, anti-HIV and anti-inflammatory agents. Apart from being biologically active, they are materially useful for making polybenzoxazines. Polybenzoxazines, a novel class of non-conjugated thermosetting materials that belong to the family of addition-curable phenolic resins. They have lucrative properties such as small shrinkage in curing, low water absorption, good thermal stability, no release of volatile materials during cure, no need for catalyst and inexpensive raw materials. Further, the flexibility in designing a monomer gives polybenzoxazines an additional edge over ordinary phenolic resins. This review briefly describes the syntheses including eco-friendly strategies, biological and material significance of various dihydro[1,3]oxazine derivatives.

Cellulose sulfuric acid has proved its competence as a potential bio-compatible, non-toxic and inexpensive heterogeneous solid acid catalyst in synthetic organic chemistry. Owing to its remarkable properties such as non-hygroscopic nature, recyclability, superior catalytic activity and high stability it has been actively explored as an efficient and biodegradable organocatalyst in diverse chemical transformations of synthetic relevance. This review attempts to summarize a significant advancement and catalytic applications of cellulose sulfuric acid for the synthesis of plethora of biologically relevant organic molecules

: Microwave-accelerated methods have emerged as powerful tools in organic synthesis to enhance the reaction rates and provide products with high yields, improved selectivity, lower energy consumption, mild reaction conditions and negligible waste generation. Xanthenes are an important class of biologically important oxygen containing heterocyclic molecules that possess a multitude of pharmaceutical properties. By considering the medicinal and material significance of these molecules, a large number of synthetic methodologies and catalytic systems have been reported for the synthesis of a wide range of xanthenes in the past. However, the focus of the present review is to summarize the various microwave-assisted protocols for the synthesis of diverse substituted xanthene analogues.