2‐Bromo‐2‐chloro‐3‐arylpropanenitriles can be prepared by Meerwein reaction from 2‐chloroacrylonitrile and various aryldiazonium salts under copper(II) bromide catalysis. They proved to be stable compounds which form 2‐chlorocinnnamonitriles upon treatment with bases. Reaction of the title compounds with substituted thioglycolates gave substituted 3‐aminothiophenes which have not yet been accessible by other routes. Three‐component reactions with the title compound, sodium sulfide and bromonitromethane, chloroacetonitrile, or ethyl 4‐chloroacetoacetate gave 2‐nitro‐ and 2‐cyano‐substituted 3‐aminothiophenes, and thienopyridinediones in high yields and in one single step, respectively.
Methyl 3-aryl-2-bromo-2-chloropropanoates can be prepared by Meerwein reaction from methyl 2-chloroacrylate and various arenediazonium salts under copper(II) bromide catalysis. The resulting readily available compounds were used as starting materials in reactions with substituted methanethiols for the construction of substituted 3-hydroxythiophenes which have not yet been accessible by other routes. Structural variety of the obtained 2-substituted 5-aryl-3-hydroxythiophenes has been achieved due to a wide range of available starting materials, including both anilines and thiols.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.