The most obvious, and known, approach to rac-PZQ is using Reissert chemistry.
 
 
This approach has been used in the following publications:
 [1]    Organic Sonochemistry. Synthesis and Use of Reissert compounds under PTC-Ultrasound, J. Ezquerra and J. Alvarez-Builla, J. Heterocyclic Chem. 1988, 25, 917-925.

[2]    Alkylation of isoquinolines via 2-benzoyl-1,2-dihydroisoquinaldonitriles: 1-Benzylisoquinoline, B. C. Uff, J. R. Kershaw and J. L. Neumeyer, Org. Synth. 1988, 6, 115; Org. Synth. 1977, 56, 19.
 
Child pages from this one detail attempts at this synthesis, and can host comment about it.