Preparation method of BTK degradation agent

The method has the advantages of mild reaction conditions, no high-temperature and high-pressure reaction, low toxicity or no toxicity of raw materials, simplicity in operation, high reaction yield, high product purity, convenience in post-treatment, good reproducibility and suitability for industrial production. 涉及一种式(I)所示的化合物及其中间体的制备方法，该方法反应条件温和，不涉及高温、高压反应，原材料低毒或无毒，操作简单，反应产率高，产品纯度高，后处理方便，重现性好，适合于工业化生产。