Dibromomethane as One‐Carbon Source in Organic Synthesis: The Mannich Base Formation from the Reaction of Phenolic Compounds with a Preheated Mixture of Dibromomethane and Diethylamine

Abstract

The salt formed from the reaction of dihalomomethane and diethylamine reacted with phenolic compounds to give the corresponding Mannich bases in modest to good yields. As for the relative rates and yields are in the following order: CH₂Br₂ > CH₂Cl₂. The CD₂Cl₂ is also applicable to prepare the deuterated analogues. At higher temperature, the elimination of diethylamine from Mannich base occurred to give the corresponding o‐quinone methide intermediate, which was then trapped by another phenolic compound to give bis(2‐hydroxy‐1‐aryl)methanes.

Keywords:

• Mannich base
• o‐Quinone methide
• o‐Naphthoquinone methide
• Naphthol
• Dibromomethane
• Diethylamine

Acknowledgments

We are grateful to the National Science Council, National Chung Cheng University, and Academia Sinica, Republic of China for financial support.