1. E. E. Korshin, R. M. Eliseenkova, T. A. Zyablikova, L. G. Zakharova, A. G. Akhmadullin, V. D. Nusinovich, and Ya. A. Levin,Izv. Akad. Nauk, Ser. Khim., 1993,1116 [Russ. Chem. Bull., 1993,42, 1071 (Engl. Transl.)].
2. R. J. Grout, inThe Chemistry of Amidines and Imidates, Ed. S. Patai, Interscience, London, 1975, 255.
3. M. V. Rubtsov and A. G. Baichikov, inSinteticheskie khimiko-farmatsevticheskie preparaty [Synthetic Chemicopharmaceutical Preparations], Meditsina, Moscow, 1971, 169 (in Russian).
4. US Pat. 4343810,Chem. Abstrs., 1982,97, 175075.
5. US Pat. 4344958,Chem. Abstrs., 1982,97, 188298.