@article{oai:kutarr.kochi-tech.ac.jp:00000136,
 author = {Wang, Pengyu and Nishimura, Daigo and Komatsu, Takaya and Kobiro, Kazuya},
 issue = {3},
 journal = {Journal of Supercritical Fluids},
 month = {Oct},
 note = {Environmentally benign, non-catalytic, simple, and complete aromatic ring methylation of catechol derivatives by using 1,3,5-trioxane as the source of methyl groups was investigated in subcritical and supercritical water and under solvent-free conditions. Irrespective of the presence of subcritical and supercritical water as a reaction medium, catechol and 4-methylcatechol afforded the permethylation product 3,4,5,6-tetramethylcatechol. Only a small amount of 3,4,5,6-tetramethylcatechol (2% yield) was obtained under solvent-free conditions at 400 °C for 10 min. However, supercritical water considerably accelerated the formation of 3,4,5,6-tetramethylcatechol (13% yield) under the conditions of 400 °C, 10 min, and 0.35 g/mL water density.},
 pages = {360--364},
 title = {Simple, Non-catalytic Permethylation of Catechol Derivatives in Subcritical and Supercritical Water},
 volume = {58},
 year = {2011}
}