An Improved Method for the Preparation of 4,5-Diaminochrysazin

Abstract

4,5-Diaminochrysazin was prepared from chrysazin by ethylation and nitration followed by reaction with hydroiodic acid (HI). Treatment of 1,8-diethoxy-4,5-dinitroanthraquinone with HI resulted not only in O-deethylation, but also in reduction of nitro groups with more than 95% yield. This is a unique finding and is reported for the first time with a definite improvement over literature methods and is suitable for scale-up.

Keywords:

• Anthraquinone
• deethylation
• ethylation
• nitration
• reduction

ACKNOWLEDGMENTS

The authors thank Dr. Anil Kush, CEO, Vittal Mallya Scientific Research Foundation, for his encouragement and Mr. A. C. Karunakara for analytical support.