Preparation method for key intermediate of neotame--3,3-dimethylbutyraldehyde

The invention provides a preparation method for key intermediate of neotame--3,3-dimethylbutyraldehyde, comprising the following steps: under nitrogen protection in a vessel, organic solvent and a solid acid catalyst are added, tert-butyl chloride and aryl acid vinyl esters are dropped; through a thermal insulation reaction, the catalyst is filtered, the organic layer is decompressed and distilled, and alkali or acid is added for heating, backflow and hydrolysis to produce a crude product to be rectified to produce the final 3,3-dimethylbutyraldehyde product. The preparation method for the keyintermediate of neotame--3,3-dimethylbutyraldehyde has the advantages of low material cost and simple operation, moderate reaction conditions and less side reactions and is safe, environmentally friendly and beneficial for industrial production. 本发明提供种纽甜关键中间体3,3-二甲基丁醛的制备方法，在容器中，氮气保护，加入有机溶剂和固体酸催化剂，滴加叔丁基氯，再滴加芳基酸类乙烯酯，保温反应后过滤除去催化剂，将有机层减压蒸馏，再加入碱或者酸加热回流水解得粗品，粗品再精馏得3,3-二甲基丁醛成品。本发明原料成本低，反应条件温和，操作简单副反应少，安全环保，利与工业化生产。