3-Bromo-or 3-iodo-cinnoline (and 4-substituted analogues) are condensed with terminal alkynes in the presence of Pd and Cu compounds as catalysts to give the 3-alkynyl- derivatives. When 4-chloro-or 4-phenoxy-compounds are used, the products react with amines, in the presence of copper (I) iodide, to form pyrrolo [3, 2-c] cinnolines and with hydrazines to give either the same ring system or a pyrazolo [4, 3-c] cinnoline. Hydrolysis ...
