14090-76-7

168646-54-6

The following preparation was adapted from the method described by Bodige and MacDonnell (Bodige, S.; MacDonnell, F.M. Tetrahedron Lett. 1997, 38, 8159). The reaction and post-processing steps were carried out under air-free conditions, using the standard Schlenk technique or operating in a nitrogen-filled glove box. A mixture of 1,10-phenanthroline-5,6-dione (384 mg, 1.60 mmol), Pd/C (228 mg), and ethanol (60 mL) was purged with nitrogen and heated to reflux. A mixture of 15 mL of ethanol and 2.16 mL of hydrazine was added slowly and dropwise over 1.5 h. The reaction mixture was subsequently refluxed overnight. Upon completion of the reaction, it was filtered through a bed of diatomaceous earth while hot and washed three times with 7 mL of boiling ethanol. The filtrate was concentrated under reduced pressure to remove the solvent and the resulting solid was ground with water and allowed to stand at 4 °C overnight. The mixture was subsequently filtered, washed sequentially with water, dichloromethane and hexane and finally dried under vacuum to give a brown product in 70% yield. The product was characterized by 1H-NMR (400 MHz, DMSO-d6) with chemical shifts δ (ppm) of 8.78 (dd, 2H), 8.48 (dd, 2H), 7.62 (dd, 2H), 5.22 (s, 4H).