Fries rearrangement in methane sulfonic acid, an environmental friendly acid
Annie Commarieu*, Wolfgang Hoelderich, Jean Alex Laffitte and Marie-Pierre Dupont
*Atofina, Lacq Research Center, PO Box 34, 64170 Lacq, France, Email: annie.commarieuatofina.com
A. Commarieu, W. Hoelderich, J. A. Laffitte, M.-P. Dupont, J. Mol. Cat. A.: Chemical, 2002, 182-183, 137-141.
The Fries rearrangement of phenyl acetate for the paracetamol process is usually performed in hydrofluoric acid (HF). The reaction was optimized with methane sulfonic acid (MSA), a strong, stable and biodegradable acid, to give para-hydroxyacetophenone with high conversion and selectivity (up to 92% of para-isomer and 8% of ortho-isomer at 100% conversion).
Methane sulfonic acid, Fries rearrangement, para-Hydroxyacetophenone, Paracetamol