Reactions of Cinnolinecarboxylic Acids

Cinnolinecarboxylic acids undergo several useful reactions, illustrated briefly by the following classified examples gleaned from the 1972-2004 literature. 

6-Methoxy-8-nitro-4-oxo-l,4-dihydro-3-cinnolinecarboxylic acid (15, R = CO2H) gave 6-methoxy-8-nitro-4(l//)-cinnolinon (15, R = H) (Ph2CO, 190°C, 

6-Bromo-4-oxo-l-propyl-l,4-dihydro-3-cinnolinecarboxylic acid (16, R = C02 H) gave 6-bromo-l-propyl-4(l/l)-cinnolinone (16, R = H) (neat substrate. 

3-Amino-4-cinnolinecarboxylic acid 1-oxide (17) gave 3-cumoIinamine (18) (Na2S204, Me2NCHO, H2O, reflux no further details).  

Note This may be done directly or via an acyl halide. Both procedures are 

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This chapter deals with nuclear and extranuclear cinnolinecarboxylic acids and the corresponding carboxylic esters, acyl halides, carboxamides, carbohydrazides, carbonitriles, and carbaldehydes, and the ketonic acylketones. To avoid repetition, the interconversion of these cinnoline derivatives are discussed only at the first opportunity for example, the esterification of cinnolinecarboxylic acids is covered as a reaction of cinnolinecarboxylic acids rather than as a preparative route to carboxylic esters, simply because the section on acids precedes that on esters. To avoid any confusion, appropriate cross-references have been included. 

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