Three-component reactions have emerged as useful methods because the combinationof three components to generate new products in a single step is extremely economical,among the multi-component reactions. A green, simple, efficient, and cost-effective procedure has been carried out by the synthesis of dihydropyrimidinonesin Biginelli’s condensation of ethyl cyanoacetate, aldehyde and urea or thio...

The potential of tobacco waste as a viable source of medicinally important flavonoids like rutin has been investigated. Three flavonoids, apigenin, quercetin and rutin, have been isolated from waste tobacco leaves, and their identities have been confirmed by UV-visible, 1H-NMR and 13C-NMR spectroscopy. By using analytical HPLC, the amount of rutin present in the tobacco leaves, before and after...

nowadays nmr spectroscopy becomes a powerful tool in chemistry because of the nmr chemical shifts. hartree–fock theory and the gauge-including atomic orbital (giao) methods are used in the calculation of 29si nmr chemical shifts of various silicate species in the silicate solution as initial components for zeolite synthesis both in gas and solution phase. calculations have been performed at geo...