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A simple and efficient solvent-free method was developed for the acetylation of alcohols, phenols and amines in excellent yields employing glycerol-based sulfonic acid (SO 3 H) functionalized carbon catalyst under environmentally benign reaction conditions. The salient features of this protocol are the short reaction time, ease of product isolation and reusability of the carbon catalyst.

: In continuation of our efforts to find new antimicrobials, herein we report the synthesis of various pyrazole, pyrazoline, and pyridine based novel bioactive heterocycles (3a-t). Newly synthesized compounds analysed for their antimicrobial activity. Compounds 3c, 3h, 3i, 3k, 3n, and 3q were showed significant antimicrobial activity. Molecular docking study for the most active analogues DNA gyrase subunit b (PDB ID: 1KZN) corroborated well with observed antimicrobial potency exhibiting significant binding affinity. For the interpretation of the chemical structures reported in this paper were based on IR, 1H NMR, 13C NMR, and mass spectral data.

A variety of aldehydes undergo smooth coupling with N-tosyltryptamine in the presence of carbon−SO3H in ethanol at 80 °C to furnish the corresponding tetrahydro-β-carbolines in excellent yields with high selectivity. The coupling of tryptamine with isatins affords the respective spiro-tetrahydro-β-carbolines in good yields. The use of a recyclable solid acid catalyst makes this method simple, convenient, and cost-effective.

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A novel heterogeneous carbon-based sulfonated copper (SO 3 Cu-carbon) catalyst was developed for the first time and investigated its catalytic activity for the regioselective synthesis of β-hydroxy 1,2,3-triazoles by azide-alkyne cycloaddition in aqueous medium. The SO 3 Cu-carbon catalyst was prepared by the modification of the glycerol-based SO 3 H-carbon catalyst on treatment with 10% aqueous CuCl 2 solution under controlled conditions. Based on its physico-chemical characteristics the structure of the catalyst is proposed as a polycyclic aromatic carbon attached with -SO 3 Cu, -COOCu and -OCu functionalities. The catalytic activity of the SO 3 Cu-carbon catalyst was demon-strated for the one pot 'click' reaction of epoxide, sodium azide and terminal alkyne in water at 60°C for the synthesis of βhydroxy 1,2,3-triazoles in excellent yields (89-94%) without any additives. The formation of the product proceeds in one pot through a mechanism that involves in situ generation of organic azide intermediate followed by rapid ring closure with alkynes. The catalyst was easily recovered by simple filtration and reused for 5 cycles without any leaching and deactivation thus exhibiting its excellent stability and reusability. Moreover, the cascade reaction was best performed in water at moderate temperature, rendering all the processes truly green.[a] G. recyclability makes this methodology operationally convenient and does not require additives. 2 3 4 5 6 7 8

KEYWORDSA series of β-hydroxyazides were effectively synthesized from the regioselective ring opening of oxiranes by azide anion in presence of glycerol-based sulfonic acid functionalized carbon as a novel reusable heterogeneous catalyst in H2O achieving good yields (80-98%). The workup procedure was simple, and the catalyst could be reused over five times without losing its catalytic activity and selectivity.Water Oxiranes Azidolysis Sodium azide Azidohydrins Carbon acid catalyst

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