1. Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, H-1111 Budapest, Gellert ter 4, Hungary
2. Quality Process Development Department, Egis Pharmaceuticals Plc., H-1106 Budapest, Kereszturi ut 30-38, Hungary
3. Spectroscopic Research Department, Gedeon Richter Plc., H-1475 Budapest, 10, P. O. Box 27, Hungary
4. Department of Organic Chemistry, University of Szeged, H-6720 Szeged, Dom ter 8, Hungary