132934-47-5 2,3,10,11-Tetramethoxy-6,7-dihydrodibenzo(c,f)cyclopenta(ij)(2,7)naphthyridine Dibenzo(c,f)cyclopenta(ij)(2,7)naphthyridine, 6,7-dihydro-2,3,10,11-tetramethoxy-