Magnesium Bromide → 5-PHENYLDIPYRROMETHANE

Participants

Reaction Steps

In the survey of various acid catalysts for the pyrrole-benzaldehyde condensation, MgBr2 gave a good yield of 5-phenyldipyrromethane with little N-confused 5-phenyldipyrromethane and 5,10-diphenyltripyrrane. This observation prompted us to study the effect of MgBr2 on the pyrrole-mesitaldehyde condensation. Four reactions were carried out with 0.1, 0.3, 0.5 or 1.0 equiv of MgBr2 using a 100:1 ratio of pyrrole:mesitaldehyde at room temperature. For the reaction with 0.5 equiv of MgBr2, GC analysis showed 82.9% of 5-mesityldipyrromethane and 0.9% of unreacted mesitaldehyde. Among the acids surveyed, the use of 0.5 equiv of MgBr2 appeared superior for the synthesis of 5-mesityldipyrromethane.

Provenance & Evidence