1. S. V. Tsukerman, V. M. Nikitchenko, and V. F. Lavrushin, ZhOKh,32, 2677, 3971, 1962; 33, 1255, 2563, 1963.
2. S. V. Tsukerman, V. M. Nikitchenko, V. D. Orlov, and V. F. Lavrushin, KhGS [Chemistry of Heterocyclic Compounds], 232, 1967.
3. A. R. Katritzky and A. J. Boulton, J. Chem. Soc., 3500, 1959.
4. V. P. Litvinov and V. A. Morozov, Izv. AS USSR, OKhN, 232, 1961.
5. Yu. B. Bol'kenshtein, B. V. Lopatin, and V. A. Petukhov, Izv. AN SSSR, OKhN, 917, 1962.