Patent GB-1269742-A (GB)
Title: A process for the production of allylidene diacetate
Inventor: SWODENK WOLFGANG
IPC: B01J31/22
Filed: 1970-01-20
Abstract: 1,269,742. Catalysts comprising palladium. FARBENFABRIKEN BAYER A.G. 20 Jan., 1970 [29 Jan., 1969], No. 2618/70. Heading B1E. [Also in Division C2] Catalyst for use in the preparation of allylidene diacetate from allylacetate, acetic acid and oxygen comprises (a) carrier material, for example selected from silica, natural and synthetic silicates, pumice, activated carbon, titania, alumina and spinels, (b) metallic palladium or a compound thereof, for example an oxide, hydroxide, acetate, propionate, benzoate, acetylacetonate, acetylphenolate or bis (diphenylpropane-1,3-dionate), and (c) an alkali metal acetate or an alkali metal compound which is converted at least in part to an acetate under reaction conditions including a temperature of from 50 to 250‹C. The alkali metal acetate may be an acetate of lithium, sodium, potassium, cesium or rubidium. The convertible alkali metal compound may be a hydroxide, carbonate, phosphate, borate, formate, propionate, citrate, tartrate or lactate; exemplified alkali metal compounds are sodium hydroxide, sodium borate, sodium phosphate, sodium aluminate, sodium citrate, potassium carbonate, potassium hydrogen carbonate, potassium formate, potassium propionate and potassium lactate. The catalyst also may comprise material selected from copper, gold, metals of Groups V to VIII, for example ruthenium, rhodium, iridium and platinum, and comoounds of such metals, for example copper hydroxide, oxides and hydroxides of gold, ruthenium, rhodium, iridium and platinum and oxides, hydroxides, acetates, acetylacetonates and decomposition/conversion products thereof of chromium, molybdenum, tungsten, manganese and iron. Compounds which are free from nitrogen, sulphur and halogens, for example chromium acetylacetonate, manganese acetylacetonate, manganese naphthenate, iron oxide, iron hydroxide, iron acetate, iron citrate and iron acetylacetonate, preferably are used in the preparation of the catalyst; alternatively, compounds which are not free from nitrogen, sulphur and halogens, for example palladium chloride, sodium palladium chloride, copper nitrate, gold chloride, tetrachloro-auric acid, manganese sulphate, iron chloride and iron sulphate, may be used and subsequently converted to compounds which are free from nitrogen, sulphur and halogens. The catalyst may be treated with a reducing agent, for example hydrogen, ethylene, propylene, gaseous methanol or aqueous hydrazine, for example hydrazine hydrate, to convert the palladium, if present as a compound, to the metal. The catalyst, which may be in the form of pellets, "microcylinders" or spheres having a diameter of from 4 to 6 mm, may contain from 1 to 10 grams per litre of palladium, from 1 to 50 grams per litre of alkali metal acetate and, optionally, from 0.1 to 10 grams per litre of iron. Examples relate to catalysts comprising silica, 3.3 grams per litre of palladium derived from palladium acetylacetonate, 30 grams per litre of potassium acetate and, optionally, 0.6 grams per litre of iron derived from iron acetylacetonate, the silica being in the form of spheres having a diameter of 5 mm., an "inner" surface area of 110 m<SP>2</SP>/g and an apparent density of 0.5 kg/litre; preparative details of such catalysts are given.