氯氧化锆催化合成缩酮

Catalytic Synthesis of Ketal over Zirconium Oxychloride

采用DTA和吸附吡啶的FT-IR表征氯氧化锆的表面酸性,用Hamm ett指示剂测定其酸强度,以催化合成环己酮2,3-丁二醇缩酮为探针反应优化缩酮反应条件,并考察它对其他缩酮反应的催化活性,比较了不同催化剂对缩酮活性的影响。实验表明,氯氧化锆表面存在B r nsted酸中心,能使Hamm ett指示剂对-硝基苯胺(Ho=+0.99)变色,环己酮2,3-丁二醇缩酮产率可达96.5%,对其他缩酮化反应均具有良好的催化活性。且催化剂易回收,反应后处理简单,无废酸排放。

The acid property of zirconium oxychloride was characterized by means of DTA and FT-IR spectra of pyridine absorbed on the surface. Its acid strength was estimated with Hammett indictor. With ketalization between cyclohexanone and 2, 3-butanediol as a probe reaction, the optimum conditions were obtained. ZrOCl2 catalytic activity in other ketalization was investigated and its catalytic activity was compared with those of other catalysts in ketalization. The results show that the catalyst has Broensted acid centers that could change the color of Hammett indictor （p-nitrophenylamine）. The yield of cyclohexanone 2, 3-butanediol ketal is 96. 5% under the optimum conditions, and it shows excellent catalytic activity in other ketal synthesis. The catalyst could be recovered easily and the post-treatment was simple. No waste acid was discharged. The drawback brought by using conventional liquid inorganic acid to catalyze ketalization could be avoided. It is an environmental friendly catalyst to ketalization.