The invention relates to a thermal conversion vessel (200) used during amidification step of acetone cyanohydrin (ACH), in the industrial process for production of a methyl methacrylate (MMA) or methacrylic acid (MAA). The thermal conversion vessel (200) is used for converting an hydrolysis mixture of α-hydroxyisobutyramide (HIBAM), α-sulfatoisobutyramide (SIBAM), 2-methacrylamide (MACRYDE) and methacrylique acid (MAA), into a mixture of 2-methacrylamide (MACRYDE). It comprises:—at least one compartment (C1, C2, C3, . . . Ci) comprising an inner wall (206a, 206b, . . . 206i) separating said compartment into two communicating parts (C1a, C1b) by a passage provided between the bottom of said vessel and said inner wall,—said compartment having a space above said inner wall, for separating gas phase from liquid phase during thermal conversion,—said compartment being connected to an outlet valve (204a, 204b, . . . 204i). Such vessel allows obtaining a high yield thermal conversion in very safe conditions.

The invention relates to chiral imidodiphosphates and derivatives thereof having the general formula I, ##STR00001## The compounds are suitable as chiral Brønsted acid catalysts, phase-transfer catalysts, chiral anions for organic salts, metal salts or metal complexes for catalysis.

The invention relates to chiral imidodiphosphates and derivatives thereof having the general formula I, ##STR00001## The compounds are suitable as chiral Brønsted acid catalysts, phase-transfer catalysts, chiral anions for organic salts, metal salts or metal complexes for catalysis.

The invention relates to chiral imidodiphosphates and derivatives thereof having the general formula I, ##STR00001## The compounds are suitable as chiral Brønsted acid catalysts, phase-transfer catalysts, chiral anions for organic salts, metal salts or metal complexes for catalysis.

The present invention discloses a metal-catalyzed process for hydration of nitrile under the influence of the ultrasonic cavitation effect. The present invention further discloses a catalyst of formula (I), wherein the catalyst is used for process for hydration of nitrile and process for preparation thereof.

A.sub.XB.sub.YC.sub.Z   Formula (I)

The present invention provides a method for producing α-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.

A method of producing an N,N-disubstituted amide of the present invention is a method of reacting a nitrile with an alcohol in the presence of a catalyst, wherein the nitrile is a compound represented by R.sup.1CN (R.sup.1 represents an alkyl group having 10 or less carbon atoms or an aryl group having 10 or less carbon atoms), wherein the alcohol is a compound represented by R.sup.2OH (R.sup.2 represents an alkyl group having 10 or less carbon atoms), wherein the catalyst is a metal salt represented by MXn (M represents a metal cation having an oxidation number of n, X represents a monovalent anion including a substituted sulfonyl group represented by —S(═O).sub.2—R.sup.3 (R.sup.3 represents a hydrocarbon group having 10 or less carbon atoms or a group in which some or all of hydrogen atoms in the hydrocarbon group are substituted with fluorine atoms), and n represents an integer of 1 to 4), a substituent bonded to a carbon atom in a carbonyl group of the N,N-disubstituted amide is R.sup.1, and two substituents bonded to nitrogen atoms in an amide group are both R.sup.2.

A method of producing an N,N-disubstituted amide of the present invention is a method of reacting a nitrile with an alcohol in the presence of a catalyst, wherein the nitrile is a compound represented by R.sup.1CN (R.sup.1 represents an alkyl group having 10 or less carbon atoms or an aryl group having 10 or less carbon atoms), wherein the alcohol is a compound represented by R.sup.2OH (R.sup.2 represents an alkyl group having 10 or less carbon atoms), wherein the catalyst is a metal salt represented by MXn (M represents a metal cation having an oxidation number of n, X represents a monovalent anion including a substituted sulfonyl group represented by —S(═O).sub.2—R.sup.3 (R.sup.3 represents a hydrocarbon group having 10 or less carbon atoms or a group in which some or all of hydrogen atoms in the hydrocarbon group are substituted with fluorine atoms), and n represents an integer of 1 to 4), a substituent bonded to a carbon atom in a carbonyl group of the N,N-disubstituted amide is R.sup.1, and two substituents bonded to nitrogen atoms in an amide group are both R.sup.2.

A method of producing an N,N-disubstituted amide of the present invention is a method of reacting a nitrile with an alcohol in the presence of a catalyst, wherein the nitrile is a compound represented by R.sup.1CN (R.sup.1 represents an alkyl group having 10 or less carbon atoms or an aryl group having 10 or less carbon atoms), wherein the alcohol is a compound represented by R.sup.2OH (R.sup.2 represents an alkyl group having 10 or less carbon atoms), wherein the catalyst is a metal salt represented by MXn (M represents a metal cation having an oxidation number of n, X represents a monovalent anion including a substituted sulfonyl group represented by —S(═O).sub.2—R.sup.3 (R.sup.3 represents a hydrocarbon group having 10 or less carbon atoms or a group in which some or all of hydrogen atoms in the hydrocarbon group are substituted with fluorine atoms), and n represents an integer of 1 to 4), a substituent bonded to a carbon atom in a carbonyl group of the N,N-disubstituted amide is R.sup.1, and two substituents bonded to nitrogen atoms in an amide group are both R.sup.2.

Disclosed are a type of halogenated conjugated diene compounds (1), and preparation and application thereof. In this method, a conjugated diene compounds is subjected to halogenation reaction to prepare the compound (1). This disclosure further provides a method of preparing a 2-arylmalonic acid derivative from the compound (1) through dehydrohalogenation and aromatization reaction. ##STR00001##