So far as it is known that no derivatives of cinnoline occurs in nature. The cinnoline ring system was discovered in 1883 by Von Richer1-9. Who in the course of experiments designed to convert O-nitro phenyl propionic acid into O-hydroxy acetophenone found that the diazonium chloride derived from O-amino phenyl propionic acid which was transformed in a ring on heating into a nitrogenous derivative. The new ring system so formed was named cinnoline (I).
Cite this article:
Dilesh Indorkar, N. Gautam, O.P. Chourasia, S.N. Limaye. Synthesis and Characterization of Cinnoline (Benzopyridazine) and Cinnoline based Pyrazoline Derivatives and Biological Activity. Asian J. Research Chem. 6(9): September 2013; Page 832-838.