Synthesis of substituted quinolines and heterocyclo[x,y-c]quinolines by the nucleophilic substitution and rearrangements of 4-chloro-2-methyl-3-nitroquinolines

4-Chloro-2-methyl-3-nitroquinolines 1-5 were used as precursors for the syn thesis of heterocyclo[c]quinolines, where the nitro group plays different r oles in the cyclization processes. Reduction of the 4-amino-3-nitro derivat ives 6-10 to the 3,4-diaminoquinolines 11-14, and subsequent condensation w ith carbonyl compounds gave the corresponding imidazo[4,5-c]quinolines 15-2 4. Condensation of 1-5 with benzylamine or amino acids and subsequent cycli zation gave the respective 3-hydroxy-2-phenylimidazo[4,5-c]quinolines 30-34 , and 35-43; 35 was cyclized to the imidazo[4,5-c]quinoline 44. Heating the 4-azido-3-nitroquinaldine 45 in benzene gave 1,2,5-oxadiazolo[3,4-c]quinol ine 46. Reaction of 2-5 with, salicylaldehyde and salicylic acid gave 47-50 and 51-54, respectively. Cyclization of either 47 or 51 and 58 or 52 gave the corresponding benzopyrano[3,2-c]quinolines 55 and 56.