Reaction of 2-Substituted 7,7-Dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic Acids with Hydrazine. Synthesis of 5-Substituted 8,8-Dimethyl-3,7,8,9-tetrahydro-2H-pyrido[4,3,2-de]cinnolin-3-ones.

The reaction of 2-substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids with hydrazine was studied. This reaction gave 5-substituted 8,8-dimethyl-3,7,8,9-tetrahydro-2H-pyrido-[4,3,2-de]cinnolin-3-ones in good yields. A possible reaction mechanism was discussed using nonempirical quantum-chemical calculations.