Synthesis
The compound was prepared based on known methods with some modifications [19,20]. O-phenylenediamine (27 g, 0.25 mol) was dissolved in 500 mL of 4 M HCl, mixed with a solution of ethanoic acid (34.2 g, 0.45 mol) in 250 mL of 4 M HCl, stirred and heated under reflux conditions for 2 hours. Upon completion of the reaction, the reaction mixture was slowly cooled to room temperature and subsequently alkalized to pH neutral with aqueous sodium hydroxide. The precipitated solid was separated by filtration, dried and purified by recrystallization using hot water (Scheme 1). Product I was obtained: white to light brown powder, melting point 171-174 °C, yield 89.1%.
References
[1] Molecules, 2015, vol. 20, # 8, p. 15206 - 15223
[2] Bulletin of the Chemical Society of Ethiopia, 2014, vol. 28, # 3, p. 451 - 456
[3] Monatshefte fur Chemie, 2016, vol. 147, # 12, p. 2209 - 2220
[4] Patent: CN106905241, 2017, A. Location in patent: Paragraph 0127-0129
[5] Patent: CN107118249, 2017, A. Location in patent: Paragraph 0117; 0118; 0119
