[Chemical and pharmacological research on pyran derivatives. XV. Phenyl-substituted 2-(dialkylamino)chromones].

Some 2-(dialkylamino)chromones phenyl substituted in position 6 or 7 or 8 were synthesized by reaction of N,N-dialkylethoxycarbonylacetamides with 4- or 3- or 2-biphenylol, respectively, in the presence of phosphorus oxychloride. The pharmacological activity of these compounds was then evaluated and compared with that shown by naphthopyran derivatives of structures (I), (II), and (III). With this same purpose also 6- and 8-benzyl derivatives of 2-(dialkylamino)chromones were prepared by using in the reaction 4- or 2-benzylphenol. Pharmacological screening showed that 6-phenyl substituted 2-(dialkylamino)chromones maintained the antireserpine and antimetrazole acti-activities which were possessed by the 1H-naphtho[2,1-b]pyran derivatives (I) and the 4H-naphtho[2,3-b]pyran derivatives (II), whereas 7-phenyl substituted compounds were devoid of any activity. 8-Phenyl substituted 2-(dialkylamino)chromones maintained to some extent the antiamphetamine activity which was clearly shown by the 4H-naphtho[1,2-]pyran derivatives (III). Furthermore, the compounds bearing the benzyl substituent both in the 6 or 8 position showed only antimetrazole activity.