i. Z. Weidenhoffer and S. Hala, Sb. Ved. Pr. Vys. Sk. Chemickotechnol. (Prague), D22, pp. 7-84 (1971). 2. US Patent No. 3,.450,761 (1969). 3. US Patent No. 3,450,744 (1969). 4. French Patent No. 1,588,472 (1970). 5. F.N. Stepanov, G. I. Danilenko, E. I. Dikolenko, et al., Vestn. Kiev. Politekh. Inst., Ser. Khim. Mashinostroeniya, No. 6, pp. 59-63 (1969). 6. F.N. Stepanov and Yu. I. Srebrodol'skii, Zh. Org. Khim., No. 2, pp. 97-100 (1966). 7. H. Stetter, J. Weber, and C. Wulff, Chem. Ber., 97, 3488-3492 (1965). 8. F.N. Stepanov and Yu. I. Srebrodol'skii, Zh. Org. Khim., No. 2, pp. 1612,1615 (1966). 9, V.I. Votyakov, A. G. Moroz, Z. S. Rod'ko, et al., The Molecular Biology of Viruses and the Chemotherapy and Chemoprophylaxis of Viral Infections [in Russian], Moscow (1974), pp. 126-134.