Preparation method of 5-bromo-valeric acid

The invention relates to a preparation method of 5-bromo-valeric acid. The preparation method particularly includes: subjecting 5-chlorine-3-pentenoic acid ester to hydrolysis reaction, hydrogenation reaction and bromination reaction to obtain 5-bromo-valeric acid, wherein 5-chlorine-3-pentenoic acid ester is one of or multiple of 5-chlorine-3-pentenoic acid methyl ester, 5-chlorine-3-pentenoic acid ethyl ester, 5-chlorine-3-pentenoic acid propyl ester and 5-chlorine-3-pentenoic acid butyl ester. The preparation method is high in finished product yield, low in production cost, simple and easy to control and easy for industrial production, and using of high-toxicity substances like benzene and sodium cyanide is avoided, so that safety is high. 本发明涉及一种5?溴戊酸的制备方法，具体方法是5?氯?3?戊烯酸酯经过水解反应、氢化反应和溴代反应三步制得，所述5?氯?3?戊烯酸酯为5?氯?3?戊烯酸甲酯、5?氯?3?戊烯酸乙酯、5?氯?3?戊烯酸丙酯、5?氯?3?戊烯酸丁酯之中的一种或多种。本发明制备方法成品收率高、生产成本低、简单易控，易于工业化生产，同时避免使用苯、氰化钠等高毒性物质，安全性高。