| 摘要 |
Substituted hydroxyhydrocinnamate esters of the formula (I)where R is alkyl, n is 0 to 2, m is 1 to 4 and A is alkyl, interrupted or uninterrupted alkylene, alkanetriyl or pentaerythrityl, are prepared by continuous transesterification of the corresponding lower alkyl mono-ester with an alkanol or polyol of the formula A-(OH)m. This novel process comprises continuously introducing into and reacting the reactants in a heated distillation column reactor having a reaction zone which contains a solid, heterogeneous transesterification catalyst to form the compound of formula (I) and the corresponding lower alkanol; separating the products so formed based on their difference in volatility; and continuously removing said products from the distillation column at a steady rate, thereby preventing the reaction mixture from reaching chemical equilibrium. The continuous reaction results in improved product throughput and product quality and has a lower residence time, as compared to known batch-type processes.
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