In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Synthesis and action on the central nervous system of some N2-substituted cinnoline derivatives, published in 1994-06-30, which mentions a compound: 137195-33-6, Name is 2,3-Dihydrocinnolin-4(1H)-one hydrochloride, Molecular C8H9ClN2O, Synthetic Route of C8H9ClN2O.
Alkylation of 4-hydroxycinnolines using Et bromoacetate resulted in N2-substituted acetic acids. These acids were converted to esters and amides. Some of the obtained acids were reduced with zinc dust to give 4-oxo-1,2,3,4-tetrahydro-2-cinnolineacetic acids. Several of the compounds were tested for their effect on central nervous system.
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Reference:
Cinnoline – Wikipedia,
Cinnoline – an overview | ScienceDirect Topics