The reaction of sodium enolate of diethyl (2-oxoprop-1-yl)phosphonate with N-(1-tosylprop-1-yl)thiourea results in a stereoselective formation of diethyl (4R*,5R*,6R*)-6-ethyl-4-hydroxy-4-methyl-2-thioxohexahydropyrimidine-5-phosphonate which is transformed into diethyl 4-ethyl-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-phosphonate and diethyl (4R*,5S*,6R*)-4-ethyl-6-methyl-2-thioxohexahydropyrimidine-5-phosphonate by acid-catalysed dehydration and stereoselective reduction with NaBH4 - CF3COOH, respectively.

A number of a-alkoxyestradiols were prepared through LiAlH 4 reduction of a suitably protected 6a,7a-epoxyestra-1,3,5(10)-trien-3-ol-17-one, alkylation of the resultant 7a-hydroxyestra-1,3,5(10)-trien-3-ol-17-one derivative and subsequent transformation of the C17 functionality. The stereochemistry of the products was investigated by 2D NMR spectroscopy.

The reaction of anilines, having electron-withdrawing substituents such as chloro- or trifluoromethyl groups, with acetoacetates was studied. Using the "watering protocol" [5], mainly acetanilides were obtained which were intended ty cyclize to 2-quinolones. However, in contrast to electron-rich anilides, it was not possible to obtain cyclized products from electron-deficient anilides.

5-Amino- and 5,7-diamino-pyrido[2,3-d]pyrimidine-2,4-diones were prepared easily from the corresponding 5,7-dichloro-pyrido[2,3-d]pyrimidine-2,4-diones with aliphatic and aromatic amines. The 7-monoazides, obtained by azidation of the chlorides, were converted to iminophosphoranes by reaction with triphenylphosphane via Staudinger reaction. Hydrolysis produced in one step 7-amino-pyrido[2,3-d]pyrimidine-2,4-diones.

The unexpected substitution of fluorine atoms and phenoxy groups linked to quinoxaline or benzofuroxan rings is described. The synthesis of 2-benzyl and 2-phenoxy3-methylquinoxaline 1,4-di-N-oxide derivatives was based on the classical Beirut reaction. The experimental conditions (reaction solvent and catalyst) were explored with the aim of obtaining the target compounds.

The oxidation of alkenes with molecular oxygen under atmospheric pressure in the presence of new polyaniline supported catalyst 1 has been studied. This catalyst turned out to be efficient and selective for oxidation of some unsaturated organic compounds. Oxidation of alkenes and cycloalkenes give corresponding as a main product mono-epoxy derivatives.

A set of regioisomeric 2-substituted pyridazin-3(2H)-ones containing a 3-oxo-3- phenylprop-1-en-1-yl fragment at either position 4, 5 or 6 and 2-substituted pyridazin-3(2H)-ones containing the same fragment both at positions 4 and 5 have been synthesized and evaluated as antiplatelet agents. The study allows the identification of a new highly potent platelet aggregation inhibitor (4c) as well as the formulation of preliminary structure-activity relationships in this series.

Several applications of polystyrene-supported 1,1,3,3-tetramethylguanidine (PS-TMG) in synthetic organic chemistry have been explored. This study evidenced the effectiveness and versatility of this new member of the supported guanidine superbases as an attractive candidate to replace the bases usually employed in organic synthesis during the implementation of environmentally friendly preparative processes.

(Het)arylamidoguanidines were synthesized from corresponding hydrazides and S-methyl isothiourea. They were screened in vitro for anticoagulant activity using whole canine blood. The most active compounds, namely 4-methylbenzamidoguanidine and nicotinamidoguanidine were also tested on platelet free plasma. No effect was observed for these compounds on the clotting time of platelet free plasma. Therefore, platelets were suspected as a possible target for the anticoagulant activity of the (het)arylamidoguanidines.

Bioreduction of ethyl acetoacetate with free and immobilized yeast whole cell was achieved by using water and sucrose combination. After detachment from immobilized beads under basic condition, the corresponding ethyl(S)-(+)-3-hydroxybutanoate was isolated with 98 to 100% yield. Immobilized beads of yeast whole cell were prepared at different temperature which affects the morphology and physiology of the beads for the diffusion of the enzyme, which shown the maximum conversion of the products as compared to the free yeast whole cell.