The synthesis of N-vinyluracil, N-vinylthymine, and N-vinyladenine is described. The general procedure consists of the conversion of the corresponding nucleic acid bases t o their N-hydroxyethyl compounds, followed by chlorination to N-chloroethyl compounds and dehydrochlorination to the N-vinyl derivatives. ZUSAMMENFASSUNG:Die Synthese van N-Vinyluracil, N-Vinylthymin sowie N-Vinyladenin wilrde beschrieben. Diese drei N-Vinylverbindungen wurden ausgehend van den entsprechenden Nucleinsaurebasen iiber die N-Hydroxyathylderivate und die durch Chlorierung erhaltenen N-Chlorathylderivate dargestellt. * ) 216. of the series: K. TAKEMOTO, M. IZUBAYASHI, and M. IMOTO, Makromolekulare Chem. 119 (1968) 147 (Nr. 2825).

The viscosity lowering of toluene solutions of isobutylene-isoprene rubber, polyisobutylene, and ethylene-propylene rubber in the reaction with dicumyl peroxide was investigated. By using the kinetic equations for the reaction of rubber with peroxide which had been derived previously by KIRIYAMA et al. the results of the experiments are discussed. ZUSAMMENFASSUNG : Die Abnahme der relativen Vmkositiit von Toluollosungen von Isobutylen-Isopren-, Polyisobutylen-sowie dthylen-Propylen-Kautschuk bei der Reaktion mit Dicumylperoxyd wurde untersucht , Durch Anwendung der friiher von KIRIYAMA et al. abgeleiteten Gleichungen auf die Reaktion von Kautschiik mit Peroxyd werden die Ergebnisse der Experimente diskutiert. P , + R . L P~. + R H ki, P x + R . -Py.+Pz-R ( x = Y + z ) . 78 Reaction of Dicumyl Peroxide with some Low-Olefin Rubbers DCP and rubber molecule were denoted by A and Px, respectively, where x means the degree of polymerization. Reaction (3) is a scission of the rubber molecule ; it probably occurs very difficultly : Propagation :Reaction (4) is a spontaneous scission of the rubber, for example:. CH2 CH2 CH3