| 摘要 |
The present invention relates to a novel process for the manufacture of alkenylated aromatic compounds featuring at least one hydroxy group, their ring-closure reactions to chroman derivatives, as well as the acylation of the latter and the aromatic compounds featuring at least one hydroxy group themselves. The present invention relates especially to a process for the manufacture of tocol, tocopherols and their alkanoates such as alpha-tocopherol (TCP) and alkanoates (TCPA) thereof, preferably alpha-tocopheryl acetate (TCPAc). The processes of the present invention are characterized in that at least one step of the processes is carried out in the presence of an indium salt as the catalyst. Thus, an object of the present invention is the use of an indium salt as the catalyst in Friedel-Crafts alkylation reactions of aromatic compounds featuring at least one hydroxy group and ring-closure reactions of the latter to produce chroman-ring compounds in organic solvents. According to another aspect of the invention indium salts can be used as the catalyst in processes for the manufacture of tocyl alkanoates, tocopheryl alkanoates and alkanoates of aromatic compounds featuring at least one hydroxy group by reacting tocols, tocopherol and aromatic compounds featuring at least one hydroxy group, respectively, with an acylating agent. Suitable indium salts are indium(III) salts, especially indium trichloride, indium tribromide or indium triiodide, indium(III) triflate, indium(III) bis(trifluoromethanesulfonamide) and indium(III) acetate. In preferred embodiments of the invention the processes are carried out at a pressure of at least 0.96 bar, whereby the acylation can be carried out at an absolute pressure of at least 0.02 bar.
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