Acyloxylation of alkylaromatic compounds with palladium-tin catalysts
AssigneesPhilip Morris Incorporated, Philip Morris Products S.A.
InventorsRobert L. Augustine, Setrak K. Tanielyan
Life of this patent
Estimating the term…
Abstract
This invention provides process embodiments for acyloxylation of C.sub.1 -C.sub.4 alkylaromatic compounds to produce alpha-acyloxy C.sub.1 -C.sub.4 alkyl-substituted aromatic compounds, utilizing a palladium-tin catalyst which exhibits efficient oxidation selectivity and oxidation rate stability. Toluene is acetoxylated to benzyl acetate and benzylidene diacetate.
Claims10
In a selective oxidation process which comprises reacting a C.sub.1 -C.sub.4 alkylaromatic compound with oxygen in the presence of carboxylic acid and a palladium-tin catalyst to produce an alpha-acyloxy C.sub.1 -C.sub.4 alkyl-substituted aromatic compound, the improvement which comprises employing a palladium-tin catalyst which is a product of a preparative process which comprises (1) treating a suspension of particulate inorganic support substrate in an aqueous medium with a tin salt under basic conditions to form a coating of tin hydroxide on the support surface;;
- (2) treating the tin-coated support substrate suspension in an aqueous medium with a water-soluble palladium salt to form a palladium-tin metal complex coating on the support substrate surface;
- and (3) recovering and drying the metal complex-coated support substrate to provide the catalyst.
In a selective oxidation process which comprises reacting a C.sub.1 -C.sub.4 alkylaromatic compound with oxygen in the presence of carboxylic acid and a palladium-tin catalyst to produce an alpha-acyloxy C.sub.1 -C.sub.4 alkyl-substituted aromatic compound, the improvement which comprises employing a palladium-tin catalyst which is an product of a preparative process which comprises (1) treating a suspension of particulate inorganic support substrate in an aqueous medium with a basic reagent to activate the support substrate surface;
- (2) treating the aqueous medium suspension of support substrate with a tin salt under basic conditions to form a coating of tin hydroxide on the activated support substrate surface;
- (3) treating the tin-coated support substrate suspension in an aqueous medium with a water-soluble palladium salt to form a palladium-tin metal complex coating on the support substrate surface;
- and (4) recovering and drying the metal complex-coated support substrate to provide the catalyst.
Dependencies are inferred from the claim text.