Novel synthesis of 4-(pyrazol-5 `-ylazo) isoquinoline, 4-pyrazol-5 `-ylazo) furo {[}3,4-c]-pyridine, 4-(pyrazol-5 `-ylazo) pyrrolo {[}3,4-c] pyridine and 5-(pyrazol-5 `-ylazo) pyrido {[}3,4-d] pyridazine derivatives

Pyrazol-5-ylazopentan-2,4-dione derivative A was condensed with acetonitrile derivatives to give 5-(pyrazol-5'-ylazo) pyridin-2-one derivatives la-c. Compounds I a-c reacted with benzaldehyde to give benzylidene derivatives 2a-c. 2a-c reacted with malononitrile to yield 4-(pyrazol-5'.-ylazo) isoquinoline derivatives 3a-c. Compound 3a-c could be obtained through reaction of 1a-c with alpha-cyanocinnamonitrile 4. Also, compound la-c reacted with (alpha-benzoylcinnamonitrile (5) and ethyl a.-cyanocinnamate (6) to give 4(pyrazol-5'-ylazo) isoquinoline derivative 7a-c, 8a-c respectively. Bromination of compound 1a-b yielded bromo derivative 9a,b which reacted with phenylhydrazine, ethylamine and sodium hydroxide and potassium cyanide to afford the corresponding products 10a-b-13a-b respectively 13a,b compound could be reacted with p-chlorobenzenediazoniurn chloride and p-chlorobenzaldehyde to yield the corresponding products 14a,b and 15a,b respectively. Structures of the products were established on the basis of the spectral data and elemental analyses.