Science of Synthesis

Yoon, T. P.; Jacobsen, E. N., Science of Synthesis, (2007) 20, 534.

The direct carboxylation of alkali and alkaline earth phenoxides by carbon dioxide has been used commercially in the synthesis of aromatic hydroxy acids for well over a century (‌Scheme 2‌).[‌5‌] Sodium phenoxides undergo predominantly ortho carboxylation, e.g. in the synthesis of 2-hydroxy-3-isopropyl-6-methylbenzoic acid (‌2‌), while the reactions of phenoxides with larger cations such as rubidium or cesium result in selective para carboxylation.[‌6‌] Potassium phenoxides afford mixtures of para- and ortho-potassium salicylates that rearrange upon heating to the para-isomers.[‌7‌] The reaction of simple phenols proceeds most efficiently under high pressures of carbon dioxide,[‌8‌] but catechols and higher polyhydric phenols can undergo efficient carboxylation at atmospheric pressures.[‌9‌]

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8-Meeeeee-8-eeeeeeeee-8-eeeeeeeeeeeee Meee (‌8‌):[‌88‌]

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References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8, 888.
• 8.Meeeee-Meee, (8888) 88/8, 888.
• 8.Meeeee-Meee, (8888) M 8-8, 888.
• 8.Meeeee-Meee, (8888) M 8-8, 888.