Synthesis Of The Bromination Of N-hydroxy-9,10-anthraquinone-2,3-dicarboximide

The aerobic oxidative products of hydrocarbons are important intermediates inpharmaceutical and organic synthesis. The research of the new-style and highly effi-cient catalyst is favored by people.As a small organic catalyst, NHPI attracts our attention because of its excellentcatalytic performance in aerobic oxidation of hydrocarbons. In NHPI/non-metal cata-lysis systems, anthraquinone(AQ) as co-catalyst transforming NHPI to PINO, avoidsthe disadvantages when metals act as co-catalyst. In the systems of NHPI/AQ, AQ isa one-electron transfer agent in catalyt system. The modifying of AQ maybe helpfulto the reaction.Overall consideration of NHPI converting into nitroxyl radical and AQ playingan important role as promoter, we design one-component catalyst which not only canconvert into nitroxyl radical, but also contain the structure of single electron transferagent. One the hand such a molecule can product radical by intramolecular electrontransfer, on the other hand simplify catalysis system.In this paper, we designed and synthesized nitroxyl radical catalysts: N-hydroxy-6-bromo-9,10-anthraquinone-2,3-dicarboximide (NHBADI), N-hydroxy-5,8-dibromo-9,10-anthraquinone-2,3-dicarboximide (NHDBADI) and (4-fluorobenzoyl)benzene-2,4,5-tricarboxylic acid (FBBTBA).Pyrometallitic dianhydride(PMDA) as crude material, two routes were followedin systhesizing NHBADI and NHDBADI. NHBADI was successfully prepared viamultistep reaction sequences: amination of PMDA with cyclohexane, Friedel-Craftsacylation, hydrolysis, dehydrating cyclization, acyle chlorination and nitrogenhydroxylation. FBBTBA was also synthesized with the same route. We alsoexperimented another method of synthetizing NHDBADI. PMDA, as startingmaterial, reacted with paradibromobenzene in low temperature molten salt, thendehydrating cyclization, acyle chlorinetion and nitrogen hydroxylation.Compared the above process, we can speculate that electron effect of substituent group can influence the property of AQ. For example, the reaction temperature of(2,5-dibromobenzoyl)benzene-2,4,5-tricarboxylic acid is higher than (4-bromobenzo-yl)benzene-2,4,5-tricarboxylic acid’s, but FBBTBA can not react even in higher tem-perature than (2,5-dibromobenzoyl)benzene-2,4,5-tricarboxylic acid’s. The solubilityof NHBADI and NHDBADI is very low.