Ammonium formate → 1-tert-butyl 2-ethyl 4-hydroxy-1H-indole-1,2-dicarboxylate

Participants

Reaction Steps

10% Palladium on carbon (1 g) is placed under an argon atmosphere into a round-bottom flask and covered with 50 ml of ethanol. A solution of (4-benzyloxy-indole-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester (1) (35 g, 88.5 mmol) in 250 ml ethanol is added, followed by ammonium formiate (6.3 g, 97.4 mmol). The mixture is stirred for 30 min at rt (TLC control). After completion of the reaction, the mixture is filtrated and evaporation gives a white solid, which is further purified by recrystallization from diethyl ether/hexanes.

Provenance & Evidence