| Popis: |
DURING work on the dependence of anticoagulant activity of the 4-hydroxycoumarine derivaties on chemical structure, it has been found, on the basis of infra-red and ultra-violet absorption spectra and the study of methylation products1–3, that ethyl di-(4–hydroxycoumarinyl-3)-acetate (I, pelentane) and 3,3′-methylen bis-(4-hydroxycoumarine), (II, dicoumarol) show tautomeric behaviour similar to that of the derivatives of the 2-hydroxychromone (III). This equilibrium was first described by Arndt4 in 4-hydroxycoumarine (IV). The above-mentioned equilibrium is considerably more pronounced in the bis derivatives than in 4-hydroxycoumarine itself. |
