In 1878, the structure of piperidine was still unknown, and A. W. Hofmann[REF] made attempts to add hydrogen chloride or bromine to it in the belief that the compound possessed unsaturation (i.e. he performed standard alkene classification test reactions).
Although the Hofmann-Löffler-Freytag reaction was to become a general and expeditious process for the formation of pyrrolidines, it was not until about 25 years after Hofmann's work that further examples of the reaction appeared in the literature.