 In 1912, he became a research assistant at the Kaiser Wilhelm Institute for Chemistry in Berlin, with Richard Willstätter, with whom he explored important insights on the importance of chlorophyll in carbon assimilation.In 1917, he was appointed professor of chemistry at the Ludwig Maximilian University of Munich.In the same year, he was hired as head of the pharmaceutical department of the Sandoz (now Novartis) chemical factory in Basel.