A facile one-pot synthesis of 3-aminoquinolines from ortho-aminobenzaldehydes was developed. Ethyl 6, 7-dimethoxy-3-aminoquinoline-2-carboxylate, a key intermediate for the preparation of a 4-anilino-benzo [b][1, 5]-naphthyridine-3-carbonitrile, was efficiently prepared by this method. Synthetic routes to 4-anilino-benzo [b][1, 5]-naphthyridine-3- carbonitrile and 4-anilino-benzo [b][1, 8]-naphthyridine-3-carbonitrile are described