1H-Indolo(3,2,1-de)(1,5)naphthyridine, 2,3,3a,4-tetrahydro-3-ethyl-6-methyl- 3-Ethyl-6-methyl-2,3,3a,4-tetrahydro-1H-indolo(3,2,1-de)(1,5)naphthyridine 65285-18-9