Dihalo-1-phenyl-3-methylindane prodn - by dimerising halostyrenes with phosphoric acid and an additional catalyst

摘要

Process for producing title cpds. of formula: (X = Cl or Br) is improved when. in addition to phosphoric acid, an additional catalyst (II) selected from Lewis acids, strong protonic acids, P2O5, POCl3, PCl5, SOCl2 or poly phosphoric acid is used. The cpd. 4-Cl-1(2-cephenyl)-3-methylindane is new. (I) are intermediates for dyes and parasiticides and are obtd. in high yield by a process suitable for industrial scale operation. Pref. (II) are polyphosphoric acid, SOCl2, POCl3, BF3 and AlCl3 and is 1-90 by wt. on H3PO4; the catalysts are pref. premixed before reaction. Pref. reactants are o- or p-Cl styrene, reaction is at 20-150 degrees C in solvents such as opt. chlorinated hydrocarbons at vol. ratio H3PO4 : halostyrene (or halostyrene + solvent) of 0.5 - 2 : 1.