75514-03-3

Pd and Ru nanoparticles supported on graphene oxide (GO) [Pd?GO and Ru?GO] and bimetallic [Pd/Ru?GO] were prepared and well characterized by XRD, FT-IR, EDS, TEM, XPS and ICP-AES analyses. The prepared nano-catalysts were tested for hydrodeoxygenation (HDO) of lignin monomer molecules-vanillyl alcohol and vanillin. In comparison with previously reported methods, Ru?GO and bimetallic Pd/Ru?GO catalysts showed high activity and selectivity, under milder conditions, at room temperature and 145 psi H2 pressure, for the formation of p-creosol, a value added product, as a potential future biofuel with antibacterial and anti-insecticidal properties. The multifold advantages of both these catalysts are in terms of reduced catalyst loading with a lower metal content and ambient temperture conditions resulting in higher conversion of the starting material. Furthermore, the efficacy of the developed methodology using Ru?GO and bimetallic Pd/Ru?GO catalysts under the optimized conditions was tested on the phenolic components of commercial lignin obtained by photo-catalytic fragmentation using TiO2, to obtain a mixture after HDO which contained vanillyl alcohol and p-creosol among others, as indicated by HPLC-MS analysis.

Subelliptenone F, a potent inhibitor of topoisomerase II, was synthesized for the first time via coupling of A and C ring components and B ring formation, followed by Claisen rearrangement of the 3-methyl-2-butenyl ether.

A range of chlorinated phenols which serve as standards for compounds occurring in effluents from the bleaching of wood pulps with chlorine-containing reagents has been prepared. The chlorinated phenols include chlorosyringic acids, chloroacetosyringones, chloroacetoguaiacones, 5-chloro-2-methoxy-p-hydroquinone and chloro-2,6-dimethoxy-p-hydroquinones. With the exception of the ring-chlorinated acetoguaiacones which were prepared by reaction of chlorovanillin acetates with diazomethane, the compounds were obtained by direct chlorination of appropriate phenols or their acetates. Gas chromatographic and mass spectrometric data for the acetylated phenols are given.

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