Green Oxidation of Methylarenes to Benzoic Acids with Bromide/Bromate in Water

Abstract

An efficient and convenient procedure has been developed for the oxidation of methylarenes to the corresponding benzoic acids using a bromide/bromate-based reagent system in water. Regeneration and reusability of the bromide/bromate reagent is demonstrated.

Keywords:

• Benzoic acids
• bromide/bromate
• methylarenes
• oxidation

ACKNOWLEDGMENT

The authors gratefully acknowledge the Department of Science and Technology, New Delhi, India, for financial support of this project under the Green Chemistry Task Force Scheme [No. SR/S5/GC-02A/2006].

Notes

Notes. Conditions: 10.86 mmol of 1, are in a 2:1:3 molar ratio, water, 100 °C, 8.00 h, in visible light. Product distribution is based on GC area percentages.

^a GC-MS.

^b Isolated yield.

^c Reaction carried out at rt for 16 h.

^d Constituted with multinuclear brominated and oxidized products not mentioned in the table.

^e Without visible light.

^a Isolated yields of pure products (¹H and ¹³C NMR).

^a Isolated yield.