[Chemical and pharmacological research on pyran derivatives. VIII. Synthesis of 2-dialkylamino-7-methoxychromones and derivatives].

2-Dialkylamino-7-methoxychromones were prepared by reaction of a m-methoxyphenol with N,N-dialkylethoxycarbonylacetamides in the presence of phosphorus oxychloride. Treatment of such compounds with 57% hydriodic acid resulted in the formation of the corresponding 7-hydroxy derivatives. These latter, treated with dialkylamines and formaldehyde, were transformed into the 8-dialkylaminomethyl derivatives. On the other hand the reaction of 2-dialkylamino-7-methoxychromones with morpholine and formaldehyde, in the presence of acetic acid, led to the formation of the corresponding 3-morpholinomethyl derivatives. Pharmacological investigation showed that 2-dialkylamino-7-hydroxy-chromones were without effect, whereas all other compounds tested had a clear, but generally weak, CNS stimulant activity.