1. Part X: L. Mosti, P. Schenone, G. Menozzi and G. Romussi, J. Heterocyclic Chem., in press.
2. R. Pellicciari, B. Natalini, M. Taddei, A. Ricci, G. Alunni Bistocchi and G. De Meo, J. Chem. Res. (S), 142 (1979), and literature cited therein;
3. Indian Patent 138,491 (1976);
4. Chem. Abstr., 91, 175228m (1979);
5. German Offen. 2,931,398 and 2,931,399 (1981);