1. Fischer, G. Advances in Heterocyclic Chemistry, Katritzky, A.R., Ed., New York: Academic, 2007, vol. 95, p. 143; El Ashry, E.S.H. and Rashed, N., Advances in Heterocyclic Chemistry, Katritzky, A.R., Ed., New York: Academic, 1998, vol. 72, p. 127.
2. Yang, G., Xu, L., and Lu, A., Heteroatom Chem., 2001, vol. 12, p. 491.
3. Chen, Q., Liu, Z.M., Chen, C.N., Jiang, L.L., and Yang, G.F., Chem. Biodiversity, 2009, vol. 6, p. 1254.
4. Chen, C.-N., Chen, Q., Liu, Y.-C., Zhu, X.-L., Niu, C.-W., Xi, Z., and Yang, G.-F., Bioorg. Med. Chem., 2010, vol. 18, p. 4897.
5. Schmitt, M.R., Kirsch, D.R., Harris, J.E., Beyer, C.F., Pees, K.J., Carter, P., Pfrengle, W., and Albert, G., WO Patent no. 0202563, 2002; Chem. Abstr., 2002, vol. 135, no. P96032n.