There are generally three methods for synthesizing Arbidol hydrochloride Cas number 131707-23-8. The first one is to prepare the key intermediate 5-acetyl Ethyloxy-1,2-dimethyl-1H-indole-3-carboxylic acid ethyl ester by the reaction of Nenitzescu, O-acylation and N-methylation with p-benzoquinone and ethyl 3-aminocrotonate, and then the target compound is synthesized by bromination, condensation and Mannich reaction. The method uses the Nenitzescu reaction to synthesize an anthracene ring. The rate is less than 45%, resulting the total yield is less than 25%. Class 1 solvent, 1,2-dichloroethane and carbon tetrachloride is used in the preparation process, which is difficult to use in industrial production because of its toxicity.
Secondly, thiophenol is substituted with ethyl chloroacetoacetate to introduce a phenylthio moiety in the molecule, which is then condensed with methylamine, followed by Nenitzescu reaction with p-benzoquinone, and introduction of dimethylamine by Mannich r…