Patent ID: 6441200
Filing Date: 2002-08-27
Classification: C07D,Y02P

Abstract:
A method for preparing DL-&agr;-tocopherol with high purity at a high yield, comprising:a) adding isophytol or phytol derivatives represented by Formula I or II, wherein X and Y are independently a hydroxy group, a halogen atom or an acetoxy group, to trimethylhydroquinone for the condensation thereof at 80 to 135Â° C. over 30 to 60 min in the presence of a catalyst system comprising a main catalyst component and a co-catalyst in a reaction solvent to form intermediates, said main catalyst consisting of a divalent metal halogen compound represented by MX2 wherein M is Zn2+, Fe2+ or Sn2+ and X is F, Cl or I, said co-catalyst consisting of silica gel and/or silica-alumina; b) adding a BrÃ¶nsted acid to the resultant mixture of said step a) to thereafter obtain DL-&agr;-tocopherol by separation; and c) recovering the remaining co-catalyst by washing with a polar solvent after said step b), whereby the recovered co-catalyst can be reused for the preparation of DL-&agr;-tocopherol.