Abstract
In order to examine the influence of various 6-alkoxy groups on an analgesic activity, a number of 2-phenyl-6-alkoxy-4-dimethylamino-3(2H)-pyridazinones (VII) were prepared. Pharmacological test showed that among various alkoxy groups, 6-ethoxy group is the most effective for an analgesic action. Furthermore, 2-phenyl-6-propenyl-4-dimethylamino-3(2H)-pyridazinone (XII) and 2-phenyl-1-allyl-4-dimethylamino-1, 2-dihydro-3, 6-pyridazinedione (XIII) were prepared by isomerization of 2-phenyl-6-allyloxy-4-dimethylamino-3(2H)-pyridazinone (XI), and their structures were established on the basis of physicochemical and chemical data. An analgesic activity of these compounds (XII, XI and XIII) was also less than that of 6-ethoxy derivatives (VII : R=C2H5).
