... 1. See. “Comprehensiue Heterocyclic Chemistry”, AR Katritzky and CW Rees, Editors, 1984, Pergamon Press, Vol. 3, p. 41; Vol. 4, p. 334,337; Vol. 7, p. 75 and references therein. 2. A. Kotali and PG Tsoungas, Tetrahedron Lett., 1987,26,4321. 3. A. Kotali, U. Glaveri, E. Pavlidou and PG