Magnesium Bromide → 5-Phenyldipyrromethane
Reaction equation
[NH:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]1[C:11]([CH:12]=O)=[CH:10][CH:9]=[CH:8][CH:7]=1.[Mg+2].[Br-].[Br-]>>[CH:8]1[CH:9]=[CH:10][C:11]([CH:6]([C:2]2[NH:1][CH:5]=[CH:4][CH:3]=2)[C:2]2[NH:1][CH:5]=[CH:4][CH:3]=2)=[CH:12][CH:7]=1Participants
3
Procedure
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.
Sources & evidence
- ORD record
- ord-c343fdbc7c0c4c02958b4a76144b38f6
- Source dataset
- uspto-grants-2006_04