Sonochemically enhanced Wurtz coupling using lithium metal has been investigated for a number of isomeric alkyl bromides under a variety conditions. The products result from direct coupling of short lived radicals formed at the metal surface rather than the secondary radicals which can be formed during coupling of aromatic halides and thus give rise to a single major product. Coupling has been ...

A simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([BMIm]Br) under solvent-free conditions is reported. The presented method is benefited from operational simplicity...

   Graphene oxide (GO) was prepared by an improved green chemical method using graphite flakes, KMnO4, a mixture of H2SO4/H3PO4, H2O2 and HCl. In several stages, ultrasound was used to separate the oxidized layers of GO. The use of ultrasound optimizes the effect of the reacting agents, decreasing the required amou...