Carbonylation of formaldehyde catalyzed by p-toluenesulfonic acid

A catalytic system consisting of p-toluenesulfonic acid, a transition metal complex such as CF₃SO₃Ag, and a solvent exhibits a high catalytic performance for the carbonylation of formaldehyde, followed by esterification with methanol, to produce methyl glycolate. The catalytic performance is significantly improved by using the ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, instead of organic solvents. This catalytic system shows higher yield of methyl glycolate at relatively low CO pressure in comparison to solid acid catalysts. The present system provides a potential process for synthesizing methyl glycolate via carbonylation of formaldehyde in much low corrosion in comparison to the previous system including strong inorganic liquid acids as solvents and catalysts.