1. E. Fischer and F. Jourdan, Ber.,16, 2241 (1883).
2. B. Robinson, The Fischer Indole Synthesis, Wiley-Interscience, New York (1982).
3. C. Sarbu, N. Radulescu, M. Ionescu, S. Negritescu, C. Ioan, N. Boestanu, and M. Siminovicu, Rev. Roum. Chim.,25, 245 (1980).
4. A. P. Kozikowski and Y.-Y. Chen, Tetrahedron,40, 2345 (1984).
5. R. A. Glennon, J. M. Jacyno, R. Young, J. D. McKenney, and D. Nelson, J. Med. Chem.,27, 41 (1984).