Preparation method of 1-(7-aminoheptyl) guanidine sulfate

The invention provides a preparation method of 1-(7-aminoheptyl) guanidine sulfate, and relates to the technical field of preparation of deoxyhydroxyputrescine lysine synthase (DHPS) inhibitors. On one hand, heptyl diamine and S-methylisothiourea sulfate are used as substrates, synthesis of the 1-(7-aminoheptyl) guanidine sulfate can be completed through one-step reaction, and the yield of the 1-(7-aminoheptyl) guanidine sulfate is increased; a catalyst which is strongly acidic or is difficult to separate from a product is not used, so that the method is green and environment-friendly, a reaction post-treatment method is simple and convenient, separation and purification are not needed, the yield is high, the atom economy is relatively high, and industrial production is easy to realize; on the other hand, the second mixed solution containing S-methylisothiourea sulfate is dropwise added into the first solution containing heptyl diamine, so that only amino at one end of heptyl diamine participates in the react