1. P. Neuman, J. Heterocycl. Chem., 8, 51 (1971).
2. O. Livi, G. Biagi, M. Ferretti, A. Lucacchini, and L. Berili, Eur. J. Med. Chem., 18, 171 (1983); PЖXuм, 15Zh266 (1985).
3. E. Kadem and H. Mansour, J. Chem. Soc, 1330 (1968).
4. M. Begtrap and H. Nytobt, Acta Chem. Scand., B40, 262 (1986).
5. T. Eages, M. Khan, and B. Lynch, Org. Prep. Proced., 2, 117 (1970); Chem. Abstr., 73, 109746 (1970).