| 摘要 |
Prodn. is effected by reacting the corresp. alpha-chloro acid anhydride (I) with (i) S and/or SCl2 and/or S2Cl2 and (ii) gaseous Cl2 in the presence of a Lewis acid catalyst. - (I) is pref. of formula (R1R2ClCCO)2O (where R1 is H, Cl or 1-18C alkyl and R2 is H or Cl), giving prods. of formula R1R2ClCCOCl. - The catalyst may be FeCl3, SnCl4, SbCl5, AlCl3 or AuCl3 (esp. FeCl3) and is pref. used in an amt. of 0.001-5 mole% based on (I). The amt. of reactant (i) is pref. within 10% of the stoichiometric amt., esp. 0.1-1% less than the stoichiometric amts. The total amt. of Cl is pref. 1-1.1 times the stoichiometric amt. The reaction temp. is pref. 20-200 deg.C. - By-prod. formation and pollution problems are reduced, since no HCl is formed and only 1 mole of SO2 is formed per 4 moles of (I).(0/0) |
