Study On The Process For The Preparation Of 5-Bromo-6-Fluoro-1H-Indole

As the most widely distributed heterocyclic compounds in the world, indole derivatives are playing a more and more important role in pharmaceutical, chemical and other applications.Owing to its various unique biological activities,it is vital significant that we continue to study on the process of the preparation for indole derivatives.5-bromo-6-fluoro-1H-Indole which has great application values as the pharmaceutical intermediate,however, barely has reports in domestic literatures for its synthesis.We designed a method of synthetic route in this paper.We choose 3-fluoroaniline as the starting material which undergoes amino protection,two-steps electrophilic substitution,Sonogashira reaction to structure the C-C bones,and then obtain the target product in alkaline condition eventually.In this paper we find suitable reaction conditions of the synthetic route which avoids the isomeride,controlling the product selectivity,and simplify the post-processing operation.After five-step reactions the target product yield reaches nearly 60%.The route of the preparation that we report has the industrialized prospects,which also can be reference to synthesis of substituted-phenyl indole derivatives.