Nitration of Toluene with Fluorous Biphasic System

Nitration of toluene was studied with nitro-sulfuric acid using perfluorous hexene(PFH)as solvent,and effect of reaction temperature,the molar ratio of PFH to organic solvent and reaction time on the nitration were investigated. It was observed that the optimum conditions for fluorous phase nitration of toluene was reaction temperature 50℃,n(toluene) : n(HNO3)=1 : 1.05,n(HNO3) : n(H2SO4)=1 : 1.2,m(PFH) : m(toluene)=1 : 1.8,reaction for 4 h. Conversion of toluene was 99.5%. The yield of the product mononitrotoluene was more than 98.3%, and the mass ratio of its o-and p-isomer was 1.51. The fluorous solvent and sulfuric acid can be recovered easily by simple phase separation, and reused for a number of times.