A facile access for synthesis of novel isoquinoline-based heterocycles

Hydrazonoyl halides 2, 7 and 12 react with alkyl 2-(3,4-dihydro-6,7-dimethoxy-2H-isoquinoline-1-ylidene)carboxylate 1 to give 4-(3,4-dihydro-6,7-dimethoxy-2H-isoquinoline-1-ylidene)-2,5-diaryl-2,4-dihydropyrazol-3-one 6, alkyl 2-arylazo-5,6-dihydro-8,9-dimethoxy-3-alkyl(or aryl)pyrrolo[2,1-α]isoquinoline-1-carboxylate 10 and alkyl 2-(2-arylhydrazono)-2,3,5,6-tetrahydro-8,9-dimethoxy-3-oxopyrrolo[2,1-α]isoquinoline-1-carboxylate 15, respectively. The structures of the new compounds were elucidated on the basis of elemental analyses, spectral data and X-ray crystallographic analyses.