Facile synthesis of 2,3,5,6-tetrabromo-4-methyl-nitrocyclohexa-2,5-dien-1-one, a mild nitration reagent

Nitrocylcohexadienones have been applied as nitration reagents for mild, mono-nitrating reactions. The original synthesis of 2,3,5,6-tetrabromo-4-methyl-4-nitrocylcohexa-2,5-dien-1-one appeared to be difficult to pursue due to both the solvent system and reaction conditions. Therefore, we applied a modified solvent system and optimized the reaction conditions to prepare the dienone at 0°C, eventually overcome the difficulties.