[Chemical and pharmacological research on derivatives of 1H-naphto/2,1-b/pyran. IV. Substituted 1-oxo-3-dialkylamino-1H-naphto/2,1-b/pyrans].

Reaction of N,N-dialkylethoxycarbonylacetamides with substituted beta-naphthols in 3 or 6 or 7 positions with halogen, alkyl, methoxycarbonyl, methoxyl, ethoxyl in the presence of phosphorus oxychloride, led to the formation of 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans bearing substituents in 5 or 8 or 9 positions, respectively. Moreover, on account of the chemical nature of such substituents, suitable chemical transformations of these compounds afforded some other 1H-naphtho[2,1-b]pyran derivatives. Pharmacological tests showed that anticonvulsant activity was improved by introduction of methoxy or ethoxy group in 9 position of several 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans.