反应详情

31.0 4-benzyloxy-2-ethoxycarbonyl-6-methyl indole (see preparation of the primary products in connection with Example 1) are heated to boiling in a mixture of 100 ml ethanol and 100 ml water during addition of 7.0 potassium hydroxide, for 2 to 3 hours. The ethanol is then evaporated in vacuum and the remaining, water alkaline solution is acidified with conc. hydrochloric acid. The resulting precipitate is aspirated, thoroughly washed with water and dried. There is obtained 27.6 g (~95% of theory) 4-benzyloxy-2-carboxy-6-methyl indole; m.p. 178°-180° C.

1. custompreparation of the primary products in connection with Example 1)
2. temperatureare heated
3. customThe ethanol is then evaporated in vacuum
4. washthoroughly washed with water
5. customdried