Abstract: The present invention provides a method for producing ?-hydroxyisobutyric acid amide by hydration of acetone cyanohydrin under the presence of a catalyst composed mainly of manganese oxide using a reactor in which at least two reaction regions are connected in series, the method being characterized by comprising: a step (B) of cyclically supplying at least a portion of a reaction liquid withdrawn from at least one reaction region to a first reaction region (I) in the reactor; and a step (b1) of further cyclically supplying at least a portion of the reaction liquid withdrawn from at least one reaction region to at least one reaction region other than the first reaction region. The method is also characterized in that an oxidizing agent is supplied to at least one reaction region in the reactor.

Abstract: The present invention provides a method for producing ?-hydroxyisobutyric acid amide by hydration of acetone cyanohydrin under the presence of a catalyst composed mainly of manganese oxide using a reactor in which at least two reaction regions are connected in series, the method being characterized by comprising: a step (B) of cyclically supplying at least a portion of a reaction liquid withdrawn from at least one reaction region to a first reaction region (I) in the reactor; and a step (b1) of further cyclically supplying at least a portion of the reaction liquid withdrawn from at least one reaction region to at least one reaction region other than the first reaction region. The method is also characterized in that an oxidizing agent is supplied to at least one reaction region in the reactor.

Abstract: The present invention provides a method for producing ?-hydroxyisobutyric acid amide by hydration of acetone cyanohydrin under the presence of a catalyst composed mainly of manganese oxide using a reactor in which at least two reaction regions are connected in series, the method being characterized by comprising: a step (B) of cyclically supplying at least a portion of a reaction liquid withdrawn from at least one reaction region to a first reaction region (I) in the reactor; and a step (b1) of further cyclically supplying at least a portion of the reaction liquid withdrawn from at least one reaction region to at least one reaction region other than the first reaction region. The method is also characterized in that an oxidizing agent is supplied to at least one reaction region in the reactor.

Abstract: The present invention provides a method for producing ?-hydroxyisobutyric acid amide by hydration of acetone cyanohydrin under the presence of a catalyst composed mainly of manganese oxide using a reactor in which at least two reaction regions are connected in series, the method being characterized by comprising: a step (B) of cyclically supplying at least a portion of a reaction liquid withdrawn from at least one reaction region to a first reaction region (I) in the reactor; and a step (b1) of further cyclically supplying at least a portion of the reaction liquid withdrawn from at least one reaction region to at least one reaction region other than the first reaction region. The method is also characterized in that an oxidizing agent is supplied to at least one reaction region in the reactor.

Abstract: Provided is a process for producing ?-hydroxycarboxylic esters from ?-hydroxycarboxylic amides and aliphatic alcohols, wherein it is a production process which is inhibited in a production cost and enhanced in a conversion rate and a selectivity and which is industrially advantageous. To be specific, it is a production process for ?-hydroxycarboxylic ester characterized by subjecting ?-hydroxycarboxylic amide and aliphatic alcohol to a gas phase reaction in the presence of a zirconium dioxide catalyst. A catalyst lifetime is improved to a large extent by using a zirconium dioxide catalyst containing a specific element.

Abstract: Provided is a process for producing ?-hydroxycarboxylic esters from ?-hydroxycarboxylic amides and aliphatic alcohols, wherein it is a production process which is inhibited in a production cost and enhanced in a conversion rate and a selectivity and which is industrially advantageous. To be specific, it is a production process for ?-hydroxycarboxylic ester characterized by subjecting ?-hydroxycarboxylic amide and aliphatic alcohol to a gas phase reaction in the presence of a zirconium dioxide catalyst. A catalyst lifetime is improved to a large extent by using a zirconium dioxide catalyst containing a specific element.

Abstract: A process for producing a catalyst for cyanhydrin hydration, which comprises a manganese oxide as a main component and is excellent in both physical strength and reaction activity, is provided, as well as a catalyst for cyanhydrin hydration obtained by the production process. Specifically, a process for producing a catalyst which is useful for cyanhydrin hydration and contains a manganese oxide as a main component, potassium, and one or more elements selected from the group consisting of bismuth, vanadium and tin, in which the above compounds are mixed together in an aqueous system; the resulting slurry precipitate is subjected to solid-liquid separation; and the resulting hydrous cake is dried in at least two separate stages comprising a predrying and a main drying, is provided, as well as a catalyst for cyanhydrin hydration obtained by the production process.

Abstract: A process for producing a catalyst for cyanhydrin hydration, which comprises a manganese oxide as a main component and is excellent in both physical strength and reaction activity, is provided, as well as a catalyst for cyanhydrin hydration obtained by the production process. Specifically, a process for producing a catalyst which is useful for cyanhydrin hydration and contains a manganese oxide as a main component, potassium, and one or more elements selected from the group consisting of bismuth, vanadium and tin, in which the above compounds are mixed together in an aqueous system; the resulting slurry precipitate is subjected to solid-liquid separation; and the resulting hydrous cake is dried in at least two separate stages comprising a predrying and a main drying, is provided, as well as a catalyst for cyanhydrin hydration obtained by the production process.