Green Nitration of Toluene in Perfluorous Nonene

Perfluorous nonene(C9F18)can form fluorous biphase system with toluene at the nitration reaction temperature of toluene.Nitration of toluene with fluorous biphase system was studied by using the perfluorous nonene as solvent.The effects of nitration system,phase ratio of perfluorous nonene and toluene,reaction time and temperature on the yield of nitrotoluene were investigated.Experiments show that the yield of nitrotoluene can be increased by using perfluorous nonene in the nitration of equal molars of toluene and fuming nitric acid.When the nitration system is consisted of n(toluene):n(fuming HNO3):n(concentrated H2SO4):n(C9F18)= 1:1:0.2:0.52,the yield of nitrotoluene can reach 95.2% with reaction temperature of 50℃ for 5 h.It was found that 97.6% used C9F18 can be recovered,and the yields of nitrotoluene have little change during reusing the recovered C9F18 for 6 times.The post-treatment of the nitration process proposed is very simple,and the used H2SO4 can be recovered and reused too.All these show that the proposed nitration process is a good green toluene nitration process.