Preparation of diacetals of glyoxal
AssigneeBASF SE
InventorsGunnar Heydrich, Nicola Christiane Aust, Hermann Putter, Andreas Fischer, Jorg Botzem
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Abstract
A process is described for preparing diacetals of glyoxal by reacting from 40 to 75% by weight aqueous glyoxal with monohydric alcohols in the presence of an acid catalyst, which comprises leaving a liquid mixture which, at the beginning of the reaction, comprises alcohol and glyoxal in a molar ratio of at least 15:1 and also water in a concentration of not more than 8% by weight in contact with the acid catalyst until concentration in the reaction mixture of the diacetal formed reaches at least 70% of the equilibrium concentration without more than 5% by weight of the alcohol used having already been distilled off.
Claims15
A process for preparing diacetals of glyoxal by reacting from 40 to 75% by weight aqueous glyoxal with monohydric alcohols in the presence of an acid catalyst, which comprises contacting a liquid mixture which, at the beginning of the reaction, comprises alcohol and glyoxal in a molar ratio of at least 15:1 and also water in a concentration of not more than 8% by weight with the acid catalyst until concentration in the reaction mixture of the diacetal formed reaches at least 70% of the equilibrium concentration without more than 5% by weight of the alcohol used having already been distilled off.
A process as claimed in any of the preceding claims, wherein the alcohol is selected from the group consisting of completely water-miscible alcohols.
A process as claimed in any of the preceding claims, wherein the catalyst is selected from the group consisting of sulfuric acid, sulfuric monoesters, organic sulfonic acids and sulfonic acid ion exchange resins.
A process as claimed in any of the preceding claims, wherein the reaction is carried out at a temperature above 50° C.
A process as claimed in any of the preceding claims, wherein the reaction is carried out over a fixed bed catalyst.
Dependencies are inferred from the claim text.