The reactions of isoquinoline and phthalazine Reissert compounds with phthalaldehydic acids and their derivatives have been investigated as a means of synthesizing 1-(3-phthalidyl)isoquinolines. Of a variety of conditions tried those involving phase transfer were found, in general, to be the most suitable. The products, which are analogues of the convulsant alkaloid bicuculline, showed weak central nervous system depressant activity.