Preparation method of cyclen and intermediate thereof

The invention discloses a preparation method of cyclen and an intermediate thereof, specifically a preparation method of a compound as shown in a formula 4. The method comprises the following step: in water, carrying out a reduction reaction as shown in the specification on a compound as shown in a formula 3 and hydrazine hydrate, wherein X is phosphoric acid or sulfuric acid, when X is phosphoric acid, n is 4/3, and when X is sulfuric acid, n is 2. The preparation method has the advantages of low cost, simple operation, easy purification of intermediates and products, high yield and purity, and suitableness for industrial production. 本发明公开了一种轮环藤宁及其中间体的制备方法。本发明具体公开了一种如式4所示化合物的制备方法，其包括以下步骤：在水中，将如式3所示化合物与水合肼进行如下所示的还原反应，即可；其中，X为磷酸或硫酸；当X为磷酸时，n为4/3；当X为硫酸时，n为2。本发明的制备方法成本低，操作简便，中间体和产物易于纯化，收率和纯度高，适用于工业化生产。