New and highly efficient synthesis of 3-substituted 1-hydroxybenz[g]isoquinoline-5,10-diones

A new and efficient strategy for the synthesis of 3-substituted 1-hydroxybenz[g]isoquinoline-5,10-diones by reaction of 2-methoxycarbonyl-1,4-naphthoquinone with different pyridinium salts under Kröhnke conditions is disclosed. This one-step reaction was found to be dependent on the substitution pattern of the aromatic nucleus in the pyridinium salts.     

Calculation of the polymerization process of some 1,1-disubstituted cyclopropanes: the first propagation step

A theoretical study of the first steps of the polymerization propagation process of 1,1 cyano, fluoro and methyl disubstituted cyclopropanes and 1-cyano 1-amino cycloprane is presented. The thermodynamic and kinetic feasibility of the reactions are discussed through 6-31+G(d,p) Hartree–Fock calculations. The anionic initiation and propagation process follows an S_N2 like reaction path mainly governed by the differences in electron affinities between the incoming and outgoing anions, further modulated by the nature of the substituents. Main conclusions are that the π electron-withdrawing groups maintain the barrier heights low, making the process feasible from a kinetic viewpoint. The σ electron-withdrawing groups give more exothermic reactions but their reaction barriers are very high.     

Expanding the synthesis of Stöber spheres: towards the synthesis of nano-magnesium oxide and nano-zinc oxide

In order to synthesise Stöber spheres of different diameters, fixed amounts of ethanol, ammonia and water were used with varying amounts of tetraethyl orthosilicate. This simple method was further applied to the synthesis of nano-ZnO and nano-MgO from their respective precursors, zinc methoxide and magnesium ethoxide. The spherical nano-SiO₂, nano-ZnO and nano-MgO synthesised in this way were characterised by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. Preliminary investigations found that nano-ZnO and nano-MgO showed good catalytic activity in the trans-esterification reaction that converts vegetable oil to biodiesel.