1. For reviews, see for example: (a) Godfraind, T.; Miller, R.; Wibo, M. Pharmacol. Rev. 1986, 38, 321.
2. (b) Janis, R. A.; Silver, P. J.; Triggle, D. J. Advan. Drug Res. 1987, 16, 309.
3. (c) Sausins, A.; Duburs, G. Heterocycles. 1988, 27, 269.
4. (d) Mager, P. P.; Coburn, R. A.; Solo, A. J.; Triggle, D. J.; Rothe, H. Drug Design & Discovery 1992, 8, 273.
5. (e) Mannhold, R.; Jablonka, B.; Voigdt, W.; Schoenafinger, K.; Schraven, E. J. Med. Chem. 1992, 27, 229.