Catalytic chlorination of 2-chlorotoluene with gaseous chlorine to 2,6-dichlorotoluene over AlCl3, FeCl3, ZnCl2, and [BMIM]Cl-nAlCl(3) (-2FeCl(3) and-2ZnCl(2)) catalysts

摘要

Catalytic chlorination of 2-chlorotoluene (OCT) with Cl-2 to dichlorotoluene (DCT) over metal chlorides and Lewis acid ionic liquids was investigated. The catalytic activities of the metal chlorides for the selective chlorination of OCT to high value 2,6-DCT were in the order of AlCl3 > FeCl3 > ZnCl2. When the weight ratios of AlCl3 to OCT were 0.5:100-2:100 at 10-30 A degrees C for 12 h, the selectivity of 2,6-DCT was kept at ca. 33 %. The catalytic activities of the ionic liquids for the selective chlorination of OCT to 2,6-DCT were in the order of [BMIM]Cl-AlCl3 < [BMIM]Cl-2ZnCl(2) < [BMIM]Cl-2FeCl(3) < [BMIM]Cl-2.5AlCl(3) < [BMIM]Cl-2AlCl(3). When the weight ratio of [BMIM]Cl-2AlCl(3) to OCT was 2:100 at 10-30 A degrees C for 12 h, the selectivity of 2,6-DCT was kept at ca. 34 %. As compared with the metal chlorides, the ionic liquids exhibited high catalytic activities for the chlorination of OCT to DCT, correspondingly.