Letter | Published:

Isomeric O-Methyl Ethers of Ethyl di-(4-hydroxycoumarinyl-3)-Acetate (the Anti-coagulant Drug Pelentane or Thromexane)


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.

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    Knobloch, E., Kakáč, B., and Mácha, F., Chem. Listy, 46, 416 (1952).

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    Knobloch, E., and Procházka, Ž., Chem. Listy, 47, 1285 (1953), 19, 702 (1954).

  3. 3

    Knobloch, E., Coll. Czech. Chem. Comm., 1959 (in the press).

  4. 4

    Arndt, F., Loewe, L., and Resat, Un, Chem. Ber., 84, 319 (1951).

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    Procházka, Ž., and Trčka, V., Čsl. Farmacie, 4, 169 (1955).

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    Procházka, Ž., Knobloch, E., and Trčka, V., Proc. Pharm. Symp. Prague, 86 (1956).

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    Overman, R. S., Stahmann, M. A., Huebner, Ch. F., Sullivan, W. R., and Link, K. P., J. Biol. Chem., 148, 5 (1944).

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    Huebner, C. F., Sullivan, W. R., Stahmann, M. A., and Link, K. P., J. Amer. Chem. Soc., 65, 2292 (1943).

  9. 9

    Fučik, K., Procházka, Ž, and Štrof, J., Chem. Listy, 45, 488 (1951).

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