Traugott Sandmeyer (1854-1922)

Swiss chemist, born in Wettingen. He trained as a precision mechanic and learnt chemistry largely on his own, eventually becoming assistant to Victor Meyer and Arthur Hantzsch at the Zurich Polytechnic.

In 1884, while trying to prepare phenylacetylene from a benzenediazonium salt and copper acetylide, he obtained chlorobenzene: he had discovered that copper(I) salts replace the diazonium group by a halogen or a cyano group, the Sandmeyer reaction. From 1888 he worked for J. R. Geigy in Basel, where he developed dyes and a synthesis of isatin that also bears his name.