Synthesis of methyl phenyl glyoxylate via clean oxidation of methyl mandelate over a nanocatalyst based on heteropolyacid supported on clay

Abstract

Oxidation is an important class of reaction from both industrial and academic points of view. In recent years, a large number of oxidizing agents have been used for a variety of industrial reactions, but many of them are polluting, giving poor yields. Mandelates have played an important role in organic synthesis and are used in artificial flavoring and perfumes. Methyl phenyl glyoxylate, which contains two carbonyl groups, is an important intermediate used in fine chemical industry. Oxidation of methyl mandelate was carried out to prepare methyl phenyl glyoxylate, with 85% selectivity, by using hydrogen peroxide in the presence of a novel catalyst, namely, 20% w/w Cs_2.5H_0.5PW₁₂O₄₀/K-10 catalyst, which is partly substituted dodecatungstophosphoric acid supported on clay. The catalyst is a nano material and reusable. The workup is easy.