Study On The Synthesis Process Of Tetracaine Hydrochloride

Tetracaine hydrochloride is a kind of long-term ester local anesthetics. In 1928, tetracaine was firstly synthesized by Firsleb. In usual, it is in the form of hydrochloride. It’s recognized as one of the powerful anesthetic in clinical. There are many advantages, such as stable physical and chemical properties, fast action, working a long time. In clinic, it was applied to the block anesthesia, anesthesia of mucosal surface and epiduralanesthesia. It was also applied to the anesthesia of eye surface.At present, a lot of literatures about the synthesis of tetracaine hydrochloride have been reported. But many of the literatures are focused on clinical application and it is less about the research of synthesis process. The reported production process generally has disadvantages of high cost, low yield, and long reaction time and harsh conditions. It is very significant to effectively reduce the production cost, to improve the reaction yield, and to reduce the reaction time and environmental pollution.In this paper, the literatures about the synthesis of tetracaine hydrochloride were reviewed. A new synthesis route was developed through the study of synthetic routes for tetracaine hydrochloride. With cheap p-nitrobenzoic acid as raw material, ethyl p-nitrobenzoate is obtained through the reaction of the esterification with ethanol. ethyl p-nitrobenzoate is reacted with n-butyraldehyde to provide ethyl p-butylaminobenzoate. Under the basic condition, through the reaction of ethyl p-butylaminobenzoate with dimethylaminoethanol, tetracaine can be otained. At last, through adjusting the pH of tetracaine in ethanol with Hydrochloric acid, tetracaine hydrochloride is obtained. The synthetic route has less reaction steps, higher yield, shorter reaction time and milder conditions of reaction.The final product was confirmed by 1H NMR. The purity of the target compound is 99.91% by HPLC and meets the standard of drug. By optimizing the synthesis of new route, and the overall yield was 58.1%. Compared with that of the traditional synthesis process, the yield and purity of the product obtained through this route are higher. Moreover, raw materials are cheap, and the production facilities are simple.the synthesis process is suitable for industrial production.