1. Organic Chemistry, Martin-Luther University Halle-Wittenberg, Kurt-Mothes, Str. 2, D-06120 Halle (Saale), Germany
2. Section of Pharmaceutical Sciences, Neurofarba Department, University of Florence, Via Ugo Schiff 6, Sesto Florentino, 50019 Florence, Italy
3. Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy