Hans von Pechmann (1850-1902)

German chemist, born in Nuremberg. He obtained his doctorate in Greifswald in 1875 and worked for many years in Munich with Adolf von Baeyer; from 1895 he was professor at Tübingen.

He discovered diazomethane (1894) and, on decomposing it, obtained polymethylene, a polyethylene, for the first time (1898). The Pechmann condensation, which prepares coumarins from phenols and β-keto esters, also bears his name.