反应详情

The solution of 30.6 g of the thus prepared 2-benzyloxy-4-methyl-6-nitrophenyl pyruvic acid ethyl ester in a composition of 250 ml glacial acetic acid and 15 ml water is brought to boiling. The heating is removed and the solution is mixed with 33.6 g zinc dust in such a manner that the boiling temperature is maintained. 5.6 g zinc dust is additionally added and heated to boiling for 30 minutes. The mixture is aspirated from the excessive zinc dust while still hot. The filter cake is washed well with glacial acetic acid and ethanol. The precipitate resulting during the cooling of the filtrate is aspirated and dried. There is obtained 15.7 g (~59% of theory) 4-benzyloxy-2-ethoxycarbonyl-6-methylindole; m.p. 167°-168° C.

1. customThe heating is removed
2. additionthe solution is mixed with 33.6 g zinc dust in such a manner that the boiling temperature
3. temperatureis maintained
4. addition5.6 g zinc dust is additionally added
5. temperatureheated
6. washThe filter cake is washed well with glacial acetic acid and ethanol
7. customThe precipitate resulting during the
8. temperaturecooling of the filtrate
9. customdried