Boron tribromide → 2,3-di-(4-hydroxyphenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole hydrobromide

Participants

Reaction Steps

A solution of 46.5 g (0.19 mol) of boron tribromide in about 240 ml of dry methylene chloride was added dropwise with stirring over a 90 minute period to a solution of 35.0 g (0.11 mol) of 2,3-di(4-methoxyphenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole in 600 ml of dry methylene chloride maintained at -75° under a nitrogen atmosphere. The solution was then decanted and the remaining solid material was slurried with methylene chloride and water, collected by filtration and dried to give 2,3-di-(4-hydroxyphenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole hydrobromide.

Provenance & Evidence