1. Chemistry of Heterocyclic Compounds
2. Y. A. Ibrahim, Chem. Ind. (London), 585 (1978).
3. Compounds 1-9 were prepared according to the procedures cited in literature (1).
4. D. Liebermann and R. Jacquier, Bull. Soc. Chim. France, 383 (1961).
5. J. Daunis, Y. Guindo, R. Jacquier and Viallefont, Bull. Soc. Chim. France, 1975 (1972).