“…Methyl-1-(methylamino)-3H-naphtho[1,2,3-de]quinoline-2,7-dione (2), 3-Methyl-1-(ethylamino)-3H-naphtho[1,2,3de]quinoline-2,7-dione (3), and 1-[(2-Hydroxyethyl)amino]-3methyl-3H-naphtho[1,2,3-de]quinoline-2,7-dione (5). Compounds 2, 3, and 5 were prepared from 3-methylanthrapyridone-1sulfonic acid sodium salt (16) that was synthesized accordingly to the original report 18. …”