Methyl 2-azido-3-(2-bromophenyl)prop-2-enoate → methyl 4-bromo-1H-indole-2-carboxylate

Participants

Reaction Steps

A solution of 116 g (0.41 mol) of methyl 2-azido-3-(2-bromophenyl)prop-2-enoate in 1.5 l of toluene is added dropwise over 4 h, with mechanical stirring, to a solution of 2 l of toluene heated to reflux and reflux is maintained for an additional 1 h. The solvent is evaporated under reduced pressure and the residue is taken up in 2 l of cyclohexane. The precipitate is collected by filtration, washed with toluene and dried under reduced pressure 37.85 g (149 mmol) of product are isolated. The mother liquors are concentrated under reduced pressure and the residue is purified by chromatography on a column of silica gel. 12.2 g (48 mmol) of additional product are isolated.

Provenance & Evidence