Boron tribromide → 1-methyl-1H-indole-3-carboxylic acid (5-bromo-6-hydroxy-naphthalen-2-ylmethyl)-methyl-amide

Participants

Reaction Steps

A solution of 1.0 M boron tribromide in methylene chloride (55.0 mL, 54.9 mmol) in 50 mL of methylene chloride was added under nitrogen dropwise over 1.5 h to a solution of 1-methyl-1H-indole-3-carboxylic acid (5-bromo-6-methoxy-naphthalen-2-ylmethyl)-methyl-amide (8.0 g, 18.3 mmol), prepared in the previous step, in 300 mL of methylene chloride at dry ice-acetone temperature. The dry ice-acetone bath was replaced with an ice bath immediately after the addition. The reaction stirred at ice bath temperature for 2 h. At ice bath temperature, the reaction was quenched by the dropwise with water. The reaction was partitioned between methylene chloride and water. A solid formed in the organic layer and was collected by filtration. The solid was dried under reduced pressure to give 1-methyl-1H-indole-3-carboxylic acid (5-bromo-6-hydroxy-naphthalen-2-ylmethyl)-methyl-amide (6.5359 g, 84%) as a white solid, mp 189-190° C.

Provenance & Evidence