摘要:
A process for preparing .alpha.-tocopherol or .alpha.-tocopheryl acetate by reacting 2,3,5-trimethylhydroquinone with isophytol or phytol in the presence of a zinc halide condensation catalyst and a proton donor in a solvent with or without subsequent esterification with acetic anhydride, which comprisesA. carrying out the reaction in a nonpolar solvent which is only slightly water-miscible, if at all andB. introducing the required zinc halide into the reaction in the form of a mixture of from 1 to 4 mol of water per mol of zinc halide.The possibility of introducing the zinc halide required in the process according to the invention in the form of a mixture of zinc halide and water which can be readily handled and metered at from 50 to 200.degree. C. without impairing the yield and purity of the tocopherol opens the way to an advantageous recycling of the zinc halide after the reaction by separating off or extracting and recycling the zinc halide in the form of a from 60 to 90% strength by weight solution or pumpable magma.
摘要:
.gamma.-Butyrolactone is manufactured by hydrogenating maleic anhydride in the presence of butyrolactone as the solvent. The hydrogenated reaction mixture, which contains butyrolactone, succinic anhydride and succinic acid, is fractionated in a thin film evaporator.
摘要:
Catalysts, for olefin oligomerization, whose active material has the empirical formula IAPO.sub.4.[P.sub.2 O.sub.5.(H.sub.2 O).sub.n ].sub.a . (XY).sub.b Iwhere A is boron, antimony, bismuth, aluminum and/or 3 equivalents of titanium, X is NH.sub.4.sup..sym. and/or an alkali metal cation and/or one equivalent of an alkaline earth metal cation, Y is one equivalent of an anion, a is 0.02-0.2, b is 0-0.05 and n is 1-3, and a process for the preparation of these catalysts.