1. Merck Life Sciences, Upstream R&D, Frankfurter Strasse 250 Darmstadt Germany
2. Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Alarich‐Weiss‐Strasse 4 Darmstadt Germany
3. Merck KGaA, Central analytical services, Frankfurter Strasse 250 Darmstadt Germany