| 摘要 |
Process for the preparation of 2-(dialkoxymethyl)car-boxylic acid esters of the formula I (see fig. I) (I) wherein R1 is a non-aromatic hydrocarbon radical or a hetero cyclic non-aromatic radical, which apart from oxygen, nitrogen and/or sulfur atoms in the ring only contains carbon and hydrogen atoms, and each of which has 1 to 20 carbon atoms, it being possible for the radical R1 to carry 1 to 5 substituents and the substituents being identical or different and being halogen, an aryl, carbalkoxy, dialkylamino, diarylamino or cyano group or an alkoxy group, the alkyl being substituted or unsubstituted C1- to C12alkyl, or is an aryloxy group, the aryl being substituted or unsubstituted C6- to C14-aryl, a substituted or unsubstituted benzyl or phenethyl radical or an R4O-(R5O)x-R5 group, where R4 is substituted or unsubstituted C1-to C12-alkyl or C6- to C14-aryl, R5 is a branched or unbranched hydrocarbon radical having 1 to 4 carbon atoms or phenylene and x = 1 to 6, R2 is hydrogen or alkyl having 1 to 5 carbon atoms and R3 is unsubstituted or substituted C6- to C14-aryl or a radical mentioned under R1, by oxidizing .beta.-acetalization of acrylic acid esters with alcohols R1OH, wherein R1 has the meaning mentioned, in the presence of oxygen as the oxidant and of a catalyst system based on one or more metals of the platinum group and/or compounds thereof and of a copper compound, comprises carrying out the reaction at a temperature of up to 80.degree.C and in which the catalyst system contains 1 to 4 equivalents of anions, based on the sum of the metal atoms and metal cations, of which at most 3 equivalents are halide ions, the halogen having a molecular weight of at least 35.
|
