Ethyl 5-nitro-1H-indole-2-carboxylate → Ethyl 5-amino-1H-indole-2-carboxylate

Participants

Reaction Steps

5-Nitro-1H-indole-2-carboxylic acid ethyl ester (14.9 mmol) was suspended in acetone (50 ml) and added to a mixture of titanium(III) chloride (91 ml, >10% in 2M hydrochloric acid) and ammonium acetate (265 ml, 4M). The reaction was stirred for 2 h and neutralized with saturated sodium hydrogen carbonate. The mixture was extracted with ethyl acetate (100 ml) and the organic layer dried (MgSO4). The solvent was removed in vacuo to give a light brown solid which was purified by silica chromatography to give the title compound as an off-white solid (1.57 g) m/z=205 in MS ES+.

Provenance & Evidence