Halophenol Rearrangement in Lewis Acid-Catalyzed Friedel–Crafts Conditions: Evidence of Competitive Initial Protonation and Acylation

Koushik Saha; Nordin H. Lajis; Faridah Abas; Nabil Ali Naji; A. Sazali Hamzah; Khozirah Shaari

doi:10.1071/CH08084

RESEARCH ARTICLE

Halophenol Rearrangement in Lewis Acid-Catalyzed Friedel–Crafts Conditions: Evidence of Competitive Initial Protonation and Acylation

Koushik Saha ^A , Nordin H. Lajis ^A ^B ^E , Faridah Abas ^A ^C , Nabil Ali Naji ^A , A. Sazali Hamzah ^D and Khozirah Shaari ^A ^B

+ Author Affiliations

- Author Affiliations

^A Laboratory of Natural Products, Institute of Bioscience, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

^B Department of Chemistry, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

^C Department of Food Science, Faculty of Food Science and Technology, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

^D Department of Chemistry, Faculty of Applied Science, University of Technology Mara, 40450 Shah Alam, Selangor, Malaysia.

^E Corresponding author. Email: nhlajis@ibs.upm.edu.my

Australian Journal of Chemistry 61(10) 821-825 https://doi.org/10.1071/CH08084
Submitted: 27 February 2008 Accepted: 12 August 2008 Published: 6 October 2008

Abstract

Halogen rearrangement was observed during the Lewis acid-catalyzed Friedel–Crafts reaction of phthalic anhydride with bromophenols or bromoanisole. Further investigation revealed that 2-, 3-, and 4-bromophenols undergo rearrangement into other isomers under these reaction conditions. Product distribution from these reactions suggested that halogen rearrangement takes place during the s-complex intermediate of the condensation step. Furthermore, iodophenol undergoes hydrodeiodination rapidly rather than rearrangement, whereas chlorophenol does not undergo rearrangement at all.

Acknowledgements

The authors thank University Putra Malaysia and the Ministry of Science, Technology and Innovation for the funds provided under the Scientific Advancement Grant Allocation (SAGA) research funding program.

References

Halophenol Rearrangement in Lewis Acid-Catalyzed Friedel–Crafts Conditions: Evidence of Competitive Initial Protonation and Acylation

Abstract

Acknowledgements

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