Investigation of the Mechanism for BBr3 Facilitated Demethylation of Aryl-Methyl Ethers Applied to BCl3 Facilitated Ether Cleavage Based on Lewis Acidity Trends of Boron Trihalides

Authors

Heidi Conrad, Grand Valley State University

Disciplines

Life Sciences

Abstract

The three cycle mechanism of BBr₃ facilitated demethylation of anisole reported by Kosak et al. was further investigated in terms of its application to BCl₃ facilitated ether cleavage. Based on Lewis acidity trends of boron trihalides, BCl₃ is a weaker Lewis acid than BBr₃. Therefore, it may be observed that BCl₃ does not proceed through the three cycle mechanism as efficiently as BBr₃. Reactions performed by Kosak eat al. were reproduced with BCl₃ as the demethylating agent along with several other reactions with modified conditions. Significant evaporation of the reactions occurred and this phenomenon caused the amount of conversion from anisole to phenol, observed via GC-FID analysis, to be very inconsistent. However, evidence of the cleavage of anisole by BCl₃ has been observed. In order to obtain results consistent with the predictions for the three cycle mechanism, BCl₃ should be purchased in a solvent that possesses a higher boiling point to prevent evaporation.

ScholarWorks Citation

Conrad, Heidi, "Investigation of the Mechanism for BBr3 Facilitated Demethylation of Aryl-Methyl Ethers Applied to BCl3 Facilitated Ether Cleavage Based on Lewis Acidity Trends of Boron Trihalides" (2015). Honors Projects. 500.
https://scholarworks.gvsu.edu/honorsprojects/500