PROCESS FOR PREPARING CARBOXYLIC ACID CHLORIDE DERIVATIVES

PURPOSE: A method for preparing carboxylic chloride compounds whose chloride is substituted from the lactone compound is provided, to improve the production yield with lowering the reaction temperature. CONSTITUTION: The method comprises the steps of reacting lactone compound and thionyl chloride in the presence of a Lewis acid and a quaternary ammonium salt at the atmospheric pressure and at 90-100 deg.C, wherein the addition amounts of the Lewis acid, the quaternary ammonium salt and thionyl chloride are 0.1-20 mol%, 0.1-20 mol% and 1-10 equivalence based on the amount of the lactone compound, respectively. Preferably the lactone compound is represented by the formula 2a or 2b, wherein R1, R2, R3 and R4 are H, a halogen atom, an alkyl group of C1-C4 or a haloalkyl group of C1-C4; R5 is H or an alkyl group of C1-C4; and n is an integer of 1-6. Preferably the Lewis acid is selected from MgCl2, MgBr2, SnCl2, SnCl4, TiCl4, AlCl3, FeCl3, BF3Et2O, BCl3, B(OEt)3, B(OMe)3 and B(O-iPr)3.