Synthesis of some novel fused tetracyclic quinolonecarboxylic acids via 7‐methyl‐6,7,8,9‐tetrahydro‐3 H ‐imidazo[4,5‐ f ]quinoline and 6‐methyl‐5,6,7,8‐tetrahydro‐1 H ‐imidazo[4,5‐ g ]quinoline

A series of fused tetracyclic quinolonecarboxylic acids was prepared for biological evaluation. These compounds were synthesized by a route involving a regiospecific functionalization of 5‐fluoro‐2‐methyl‐1,2,3,4‐tetrahydroquinoline to obtain a series of new substituted 7‐methyl‐6,7,8,9‐tetrahydro‐3 H ‐imidazo[4,5‐ f ]quinolines and 6‐methyl‐5,6,7,8‐tetrahydro‐1 H ‐imidazo[4,5‐ g ]quinolines as convenient precursors of quinolones.