1. 13C NMR (200 MHz, CF3CO2D) data:2a: δ 175.59 (C-4, C-6), 61.43 (OCH3); 3a: δ 175.49 (C-4), 174.09 (C-6), 61.37 (O-CH3), 51.47 (N-CH3);9-OMe acridine: δ 174.8 (C-9), 67.8 (O-CH3);N-Me-9-acridone: δ 170.8 (C-9), 37.2 (N-CH3)
2. A Carbon-13 NMR Study of the Structure of 9-Acridanone and 9-Thioacridanone in Neutral and Acidic Media
3. Diphenyl ether cannot be used as a co-solvent with the solvents mentioned, because of the poor solubility of1at low temperatures (< 120°)