Nitrosylsulfuric acid in the synthesis of 5-chloroisoxazoles from 1,1-dichlorocyclopropanes

Nitrosylsulfuric acid is shown to be a usable reagent for the synthesis of 5-chloroisoxazoles from readily available 1,1-di-chlorocyclopropanes via nitrosation–heterocyclization reaction. A cytotoxicity of some of the prepared 5-chloroisoxazoles towards MCF7, A549, HEK293T and VA13 cell lines was evaluated.