Acetals of lactams and acid amides. 67. Polarographic behavior of enamines of the indoles series in anhydrous DMF

✍ Scribed by M. K. Polievktov; O. A. Petrishcheva; S. Yu. Ryabova; T. V. Golovko; V. G. Granik

• Book ID: 104781720
• Publisher: Springer US
• Year: 1991
• Tongue: English
• Weight: 507 KB
• Volume: 27
• Category: Article
• ISSN: 0009-3122
• DOI: 10.1007/bf00473996

✦ Synopsis

for 6 h at 600~ Directly before the experiment 50 ml of benzene was passed over at 550~ At the end of the addition of the starting compound, nitrogen was passed for another 30 rain, and the catalyzate was withdrawn and collected in a receiver with water cooling. 5-Vinylindole was isolated from the catalyzates on a column 20 mm in diameter and 500 mm long, filled with silica gel L 100/250, suspended in an ethyl acetate--petroleum ether (1:5) mixture, which is used as eluent. After evaporation of the solvent and recrystallization from petroleum ether, white needlelike crystals were obtained, mp 42-43~ which agrees with our previously obtained data [1]. 5-Ethylindole (0.4 g, 14%) was also obtained from the catalyzate. The yield of vinylindole was 0.7 g (26%).

Dehydrodecarboxylation of ethyl 5-ethylindole-2-carboxylate was carried out in analogy with the above-described procedure. From 4.12 g of ethyl 5-ethylindole-2-carboxylate, 0.56 g of 5-vinylindole (21%) was obtained.