Three-Component Heterocyclization of 5-(Arylmethylidene)­pyrimidine-2,4,6(1H,3H,5H)-triones with Isoquinoline and Dimethyl But-2-ynedioate

The reaction 5-(arylmethylidene)-2,4,6-pyrimidine-2,4,6(1H,3H,5H)-triones with isoquinoline and dimethyl but-2-ynedioate gave cycloaddition products, mixtures of diastereoisomeric substituted dimethyl 2-aryl-2′,4′,6′-trioxo-1′,3′,4′,6′-tetrahydro-2H,2′H,11bH-spiro[pyrido[2,1-a]isoquinoline-1,5′-pyrimidine]-3,4-dicarboxylates which were converted to the corresponding dipotassium salts by treatment with excess potassium hydroxide in ethanol. The synthesized compounds are of interest as promising intermediate products with potential antitubercular and fungicidal activities.