In a 1-l. Claisen flask is placed a mixture of 64 g. of finely divided sodium amide (Note 1) and 100 g. of acetyl-o-toluidine (Note 2). About 50 ml. of dry ether is added (Note 3), and the apparatus is swept out with dry nitrogen. Then, with a slow current of nitrogen passing through the mixture, the reaction flask (Note 4) is heated in a metal bath (Note 5). The temperature is raised to 240–260° over a 30-minute period and is maintained in this range for 10 minutes. A vigorous evolution of gas occurs, the cessation of which indicates that the reaction is complete (Note 6). The metal bath is removed, the flask is allowed to cool, and 50 ml. of 95% ethanol and 250 ml. of warm (about 50°) water are added, successively, to the reaction mixture. The decomposition of the sodium derivative of 2-methylindole, and of any excess sodium amide, is completed by warming the mixture gently with a Bunsen burner. The cooled reaction mixture is extracted with two 200-ml. portions of ether (Note 7). The combined ether extracts are filtered, and the filtrate is concentrated to about 125 ml. The solution is then transferred to a 250-ml. modified Claisen flask and distilled. The 2-methylindole distils at 119–126° /3–4 mm. as a water-white liquid, which rapidly solidifies in the receiver to a white crystalline mass. This product melts at 56–57°. The yield is 70–72 g. (80–83%) (Note 8).

The product may be further purified by dissolving it in 100 ml. of methanol, adding 30 ml. of water, and allowing the solution to stand in the ice chest for 5 hours. The pure white plates (52 g.) melt at 59°. An additional 10 g. may be recovered by cooling the filtrate after it has been diluted with about 20 ml. of water.