Summary
The anticoagulant activity of 3.3’-(benzylidene)-bis-4-hydroxycoumarin derivatives
has been estimated by one step Quick’s method. The derivatives contained the following
groups in the para position of benzylidene residue: NCS- (I), CH3-S- (II), CH3-SO-(III), CH3-S02- (IV), C2H5-S- (V), C2H5-SO- (VI), C2H5-S02- (VII). All these compounds were much more active than 3.3’-(benzylidene)-bis-4-hydroxycoumarin
itself.
Compounds possessing the ethyl chain at the sulphur atom (V, VI, VII) were more active
than methyl homologues (II, III, IV). Comparison of the activity of the series of
thio-, sulphoxy-, and sulphonyl-derivatives showed that among methyl- and ethyl-derivatives
those with the sulphoxy grouping (III, VI) displayed the greatest anticoagulant activity.
The action of sulphonyl (IV, VII) and thio-derivatives (II, V) was weaker and shortest.
The derivative with the NCS-group (I) possessed a relatively the lowest activity among
the investigated compounds. 3.3’-(p-Ethylsulphoxybenzyl-idene)-bis-4-hydroxycoumarin
(VI), with distinct biological activity reached about ½ of dicoumarol activity.