Volume 3, Issue 1

The one-pot synthesis of pyrido[2,3-d] pyrimidine derivatives has been reported via Knoevenagel-Michal addition pathways using substituted aromatic aldehydes, Cyanoacetamide and 6-aminouracil in N,N-dimethylformamide (DMF) solvent, with 4-dimethylaminopyridine (DMAP) as new organo catalyst catalyst under ultrasonic irradiation. The results showed that a series of aromatic aldehydes were effectively used to prepare the targeted pyrido [2, 3-d] pyrimidine derivatives with good to excellent yields (81-93 %) with no major effect on the yield of product by electron donating/withdrawing substituents. Short reaction time, environment friendly procedure, excellent yields, inexpensive and readily available catalyst are the advantages of this procedure. All synthesized compounds were characterized by IR, 1HNMR, 13CNMR and mass spectral data.

Various aspects of application of nonconventional support components (fulfilled alumina adsorbent and kaolin clay) and; their influence on a proportion of catalytic active and inert phases as a part of multilayered catalytic systems are reviewed. Operating experience of some elaborated catalysts for hydrocarbon oils hydrofining in the industrial reactor G-24 is also discussed.

In this work, previously undetected intermediates of several practically promising catalyst systems for ethylene polymerization and trimerization are discussed. In particular, the activation of ethylene polymerization catalysts (1) LNiCl2 (L = 2,4,6-trimethyl- (N-5,6,7-trihydroquinolin-8-ylidene)phenylamine) with AlEt2Cl and AlMe2Cl, (2) activation of bis(imino)pyridine vanadium(III) chloride L1VIIICl3 (L1 = 2,6-(ArN=CMe)2C5H3N, Ar = 2,6-iPr2C6H3; 2,6-Me2C6H3; 2,4,6-Me3C6H2; 3,5- F2C6H3) with AlMe3/[Ph3C]+[B(C6F5)]4¯ and MAO, and (3) selective ethylene trimerization catalyst (FI)TiCl3 (FI = phenoxyimine ligand with an additional aryl-OCH3 donor) with MAO have been assessed by NMR and EPR spectroscopy. The nature of ion-pair intermediates – the closest precursors of the propagating species – has been established, and the major catalyst deactivation pathways are discussed.

Mixed spinel-type oxides Co 1.8 Mn 1.2 O 4 , Ni 0.33 Co 1.33 Mn 1.33 O 4 and Ni 0.6 Co 1.2 Mn 1.2 O 4 prepared by thermal decomposition of nitrates have been studied in ethanol steam reforming reaction. Ni 0.6Co 1.2Mn 1.2O 4 demonstrated the highest activity among the oxides tested. Specificity of the cation distribution in the samples and their oxygen mobility have been studied by X-ray absorption spectroscopy and oxygen isotope heteroexchange, respectively. Doping of mixed cobalt-manganese spinel with Ni results in Mn redistribution between 3+ and 4+ oxidation states, thus increasing oxygen diffusion coefficient and the catalytic activity.