Abstract:
A method for preparing lactams by cyclizing hydrolysis of a corresponding aminonitrile is described. A method for manufacturing a lactam by reacting an aminonitrile with water in the presence of a catalyst involving placing the water and the aminonitrile in contact in vapor phase, passing the mixture of vapors through a bed of catalyst arranged in at least one tube forming a reaction chamber and recovering the lactam at the outlet of the tube is also described.
Abstract:
Hydrocarbon-based compounds containing at least one nitrile function are converted into compounds containing at least one carboxylic function, and into ester compounds from the carboxylic compounds thus obtained; such conversion entails reacting the nitrile compound with a hydroxyl basic compound in solution in a solvent at a temperature of between 80 and 150° C., in eliminating the ammonia formed, in reacting the salt obtained with a mineral acid, and then in recovering the compound containing at least one carboxylic function and, optionally, esterifying the acids obtained by reaction with an alcohol.
Abstract:
Hydrocarbon compounds having at least one nitrile function are converted into compounds having at least one carboxylic function by hydrating the nitrile functions into amide functions by reaction with water in the presence of a strong inorganic acid, and then hydrolyzing the amide functions into carboxylic functions by reaction with water and a strong inorganic acid; the carboxylic compounds thus obtained can be esterified into diesters, advantageously diester solvents.
Abstract:
The present invention relates to a process for the hydrocyanation of unsaturated compounds to unsaturated mononitrile compounds or to dinitrile compounds; It relates more particularly to a process for the manufacture of dinitriles by double hydrocyanation of diolefins, such as butadiene, comprising a recovery and separation of the catalytic system. The process for the manufacture of dinitriles of the invention by hydrocyanation of unsaturated compounds, comprising at least one stage of hydrocyanation in the presence of a catalytic system comprising an organometallic complex formed by one or more monodentate organophosphite ligands and one or more bidentate organophosphorus ligands and optionally a promoter of Lewis acid type, comprises at least one stage of separation by distillation of a reactant used in the process or of a compound formed by the reaction from a medium comprising the said catalytic system.
Abstract:
The invention relates to a method for the preparation of cyclohexanone from cyclohexane. The invention relates more particularly to a method for the production of cyclohexane whose impurity content enables cyclohexanone to be used as a raw material for the production of e-caprolactam. The inventive method consists in treating the mixture of cyclohexanol/cyclohexanone arising from oxidation of cyclohexane by oxygen in a dehydrogenation stage in order to transform cyclohexanol into cyclohexanone and the impurities present such as cyclopentenal. The inventive method makes it possible to obtain highly pure cyclohexanone which is compatible when used as a raw material in the synthesis of e-caprolactam.
Abstract:
The present invention relates to a process for the preparation of dinitriles by hydrocyanation of unsaturated nitrile compounds in the presence of a catalyst based on a metal element in the zero oxidation state and on organophosphorus ligands;the invention relates more particularly to a process for the recovery from the hydrocyanation medium of a catalyst for the hydrocyanation of unsaturated nitrites to dinitriles. It consists in controlling the concentration of unsaturated nitrites in the reaction medium resulting from the hydrocyanation reaction in order to obtain a concentration by weight of unsaturated nitrites of less than 20% in the said medium, and in then feeding the said medium to a stage of settling into two upper and lower phases. The lower phase comprises most of the catalytic system, while the upper phase is composed essentially of the dinitriles.
Abstract:
The present invention relates to a process for the hydrocyanation of unsaturated compounds to unsaturated mononitrile compounds or to dinitrile compounds; It relates more particularly to a process for the manufacture of dinitriles by double hydrocyanation of diolefins, such as butadiene, comprising a recovery and separation of the catalytic system. The process for the manufacture of dinitriles of the invention by hydrocyanation of unsaturated compounds, comprising at least one stage of hydrocyanation in the presence of a catalytic system comprising an organometallic complex formed by one or more monodentate organophosphite ligands and one or more bidentate organophosphorus ligands and optionally a promoter of Lewis acid type, comprises at least one stage of separation by distillation of a reactant used in the process or of a compound formed by the reaction from a medium comprising the said catalytic system.
Abstract:
The invention discloses a method for purifying adipic acid in water. More precisely it discloses an improvement in adipic acid crystallization or recrystallization in water, characterised in that the said crystallization or recrystallization is effected in presence of a strong proton acid and/or in the presence of carbon monoxide. This crystallization or recrystallization particularly enables the content of metal catalyst traces in the adipic acid to be reduced.
Abstract:
The present invention relates to the isolation of a palladium-based catalyst from a mixture in which it is dissolved. More specifically, the invention relates to the isolation of a palladium-based catalyst from a mixture originating from the reaction of hydroxycarbonylation of butadiene to pentenoic acids. It therefore consists of a process for the isolation of at least a portion of the palladium dissolved in a solution also containing at least 3-pentenoic acid, characterized in that the said solution is acidified and stirred with an aqueous solution of hydrochloric acid, so as to obtain two liquid phases including an aqueous phase containing at least a portion of the palladium.
Abstract:
Carboxylic acid anhydrides of the formula RCO--O--COR', e.g., acetic anhydride, are facilely prepared by reacting, in an essentially anhydrous, liquid phase containing an aprotic organic solvent, (i) a compound of the formula RX, (ii) a carboxylate of the formula (R'COO.sup.-).sub.n A.sup.n+, and (iii) carbon monoxide, said reaction being carried out in the presence of a catalytically effective amount of a salt of cobalt tetracarbonyl halide, at a temperature ranging from about 0.degree. to 200.degree. C. and under a pressure which is less than or equal to about 600 bars.