Conversion of 2-aryl-4-dichloromethylen-5(4<Emphasis Type="Italic">H</Emphasis>)oxazolones to 5-acylamino-substituted pyrimidine bases

Available polycentral unsaturated azlactones with 4-dichloromethylene group by successive treating with benzamidine and then with morpholine or its analogs were converted to substituted 5-acylamino-4-hydroxypyrimidines containing the residues of the corresponding nitrogen bases in the position 6. The structure of these cyclization products is consistent with the scheme of their preparation and has been confirmed also by ¹H NMR spectroscopy and XRD analysis.     

Preparation and characterization of iodinated poly(vinyl alcohol) microfibril

Iodination of poly(vinyl alcohol) (PVA) microfibril, which was obtained from saponification of poly(vinyl pivalate), was conducted before and after zone drawing at various conditions. The resulting PVA microfibrils were characterized by differential scanning calorimeter and scanning electron microscopy. Surface morphologies of these PVA microfibrils showed some differences between PVA microfibril iodinated after and before drawing. Crude shapes of PVA microfibrils iodinated after drawing indicated that iodine decreased the structural regularity severely. On the other hand, PVA microfibrils iodinated before drawing showed relatively ordered surfaces. This was ascribed to the enhanced molecular ordering of PVA microfibrils due on zone drawing. Iodinated PVA microfibrils showed a decrease in crystal melting temperature of about 100°C compared to the untreated sample. PVA microfibrils drawn after iodination showed relatively higher crystal melting temperature than those of microfibrils iodinated after drawing. These results were considered as the proofs of the changes in crystalline lattice of the PVA microfibrils. Effects, of drawing temperature on sublimation of iodine were also evaluated.