Novel isoquinoline derivatives from isochromen-1,3-dione

A number of novel isoquinoline derivatives have been synthesized using the readily obtainable (E)-4-(3,4-dimethoxybenzylidene)-4H-isochromene-1,3-dione, 2, via the reaction with different nitrogen nucleophiles such as cyanoethanoic hydrazide, cyclohexylamine, 2-aminothiophenol and p-toluenesulfonohydrazide. Furthermore, the reactivity of 2 towards thiophenol, and ethylcyanoacetate has been investigated.