Synthesis of N,N'-diglycosylated isoindigos.

The first N,N'-diglycosylated isoindigos were prepared by P(NEt(2))(3)-mediated dimerization of acetyl protected N-glycosyl-5-alkylisatins. Subsequent deacetylation yielded the corresponding deprotected N,N'-diglycosylated isoindigos. Isatine-N-glycosides containing an unsubstituted or alkyl-substituted heterocyclic moiety and ß-D-manno- and ß-L-rhamno configured carbohydrate substituents were successfully transformed into the corresponding isoindigos. In contrast, isatins with ß-D-gluco- or ß-D-xylo configured substituents failed to give the desired products.

Preparation and characterization of biodiesel from waste cooking oils using heterogeneous Catalyst(Cat.TS-7) based on natural zeolite.

Biodiesel is known as renewable biodegradable and less polluting material. It is produced by transesterification of triglycerides found in vegetable oil or animal fats. Many studies have been conducted on biodiesel production using homogeneous catalysts, but they are very expensive and not environmentally friendly. On the other hand, heterogeneous catalysts are cost-effective from the production process and ecofriendly. In this study, zeolite ore was used as a solid heterogeneous catalyst for the production of biodiesel by the transesterification reaction of waste cooking oils and studying the possibility of reusing it for several cycles under optimal reaction conditions. The catalyst was characterized by different techniques, such as TG-DTA, FTIR, XRD and TPD methods. High-quality biodiesel with 93% yield was obtained under optimal reaction conditions with the ratio of oil to methanol (1:9) mol, amount of catalyst (1.5% by weight of oil), at temperature (60 °C), and reaction time of 2 h. Biodiesel has been characterized using infrared spectroscopy, GC/MS, its physical and chemical specifications have been studied and compared with the American (ASTM) and European (EN) standards.