SYNTHETIC ROUTES TO THE CARCINOGEN IQ AND RELATED 3H-IMIDAZO[4,5-F]QUINOLINES

2-Amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ, 1a) and four new IQ h omologues, viz. its 7-methyl, 8-methyl, 9-methyl and 7,9-dimethyl deri vatives 1c-1f, have been conveniently synthesized from the appropriate 6-methoxyquinolines 3 rather than from the previously used less react ive and less available 6-haloquinolines. The 7-methyl, 9-methyl and 7, 9-dimethyl derivatives were also prepared by radical methylation of 1a . Synthetic routes to 1 and the related compounds 11-14 via the corres ponding thioureas 6 were also investigated. Compounds 1 and their anal ogues 6-14, modified at position 2, will be used in structure-activity studies.