摘要:
At least a fraction of at least one branched, saturated aliphatic diacid having 6 carbon atoms, for example 2-methylglutaric acid and/or 2-ethylsuccinic acid and/or dimethylsuccinic acid, is separated from admixtures thereof with adipic acid, by at least partially converting such at least one aliphatic diacid into the corresponding anhydride thereof, and removing the corresponding anhydride or the adipic acid from the medium of conversion/anhydridization, for example by contemporaneous or subsequent distillation, or by crystallization.
摘要:
Unsaturated carboxylic acids, e.g., pentenoic acids, are prepared by carbonylating an allylic butenol and/or carboxylate ester thereof with carbon monoxide, in the presence of a catalytically effective amount of an iridium catalyst and an iodinated or brominated promoter therefor, and optionally, a copromoter, notably wherein the promoter/Ir molar ratio ranges from 0.1:1 to 20:1. The final product acids, e.g., 3-pentenoic acid, are themselves readily hydroxycarbonylated, for example, into adipic acid, via reaction with carbon monoxide and water.
摘要:
The present invention relates to a process for the hydroxycarbonylation of pentenoic acids. By the process, one or a number of pentenoic acids are hydroxycarbonylated to adipic acid, by carbon monoxide and water, in the presence of a catalyst based on iridium and/or rhodium and of at least one iodinated promoter. The reaction mixture obtained is subjected to a refining operation, after having optionally been concentrated, making it possible to separate at least a part of the catalyst. The catalyst thus separated is recycled to an operation for the hydroxycarbonylation of pentenoic acids, of butadiene, or of butadiene derivatives.
摘要:
Preparation of carboxylic acids or corresponding esters by reacting an alcohol with carbon monoxide in the presence of an iridium catalyst and a halogen promoter. The reaction involves a reaction mixture composed of more than 0% to 10% water, more than 0% to 10% halogen promoter, 2% to 40% of an ester corresponding to the reaction of alcohol with the acid, soluble iodides in an amount such that the atomic ratio of iodides to iridium varies between more than 0 and 10, the carboxylic acid being used as the reaction solvent.
摘要:
A method for preparing carboxylic acids by carbonylating a reagent, particularly an alcohol, in the presence of an iridium catalyst. According to the method, the liquid phase reaction is carried out in a first zone in the presence of an iridium catalyst, and the resulting reaction mixture is partially vaporised in a second zone. The vaporised fraction containing the carboxylic acid is later purified and the unvaporised liquid fraction containing the catalyst is recirculated to the first zone. The method is characterised in that said unvaporised fraction is contacted with carbon monoxide in such a way that this compound is not returned to the second zone.
摘要:
A method for preparing carboxylic acids by carbonylating a reagent, particularly an alcohol, in the presence of a rhodium catalyst. According to the method, the liquid phase reaction is carried out in a first zone in the presence of a rhodium catalyst, and the resulting reaction mixture is partially vaporised in a second zone. The vaporised fraction containing the carboxylic acid is later purified and the unvaporised liquid fraction containing the catalyst is recirculated to the first zone. The method is charactracterised in that said unvaporised fraction is contacted with carbon monoxide in such a way that this compound is not returned to the second zone.
摘要:
Process for the preparation of a carboxylic acid or ester thereof. The process includes reacting at least one alcohol, alkyl or aryl halide, ether or ester, with carbon monoxide, in the presence of a catalytically effective amount of at least one rhodium compound or rhodium metal, at least one iridium compound or iridium metal, or at least one mixed rhodium/iridium compound, and at least one halogen-containing promoter therefor.
摘要:
Adipic acid is selectively prepared via hydrocarboxylation of pentenoic acids, by reacting water and carbon monoxide with at least one pentenoic acid, in the presence of a catalytically effective amount of a rhodium-based catalyst and at least one iodinated promoter therefor, at a temperature ranging from 100.degree. to 240.degree. C. and a pressure greater than atmospheric, and wherein (a) such reaction is carried out in the absence of a third reaction solvent and (b) the carbon monoxide partial pressure, measured at 25.degree. C., is less than or equal to 20 bar.
摘要:
.beta., .gamma.-Unsaturated carboxylic acids, e.g., 3-hexene-1,6-dioic acid, are selectively prepared by carbonylating (with carbon monoxide) an allyl alcohol, e.g., a butenediol, at an elevated temperature and under superatmospheric pressure, in the presence of a catalytically effective amount of a palladium-based catalyst and at least one quaternary onium chloride of one of the Group VB elements nitrogen or phosphorus, such element being tetracoordinated via carbon atoms and with the proviso that such nitrogen atom may be coordinated to two pentavalent phosphorus atoms.
摘要:
A method for preparing carboxylic acids including (n+1) carbon atoms, or the related esters, by liquid phase carbonylation of an alcohol including (n) carbon atoms, in the presence of a uniform catalytic system based on at least one iridium compound and at least one halogenated promoter. In particular, the method is characterised in that the content of ester related to said carboxylic acid and alcohol is kept between 15 and 35% in the medium during the reaction, while the halogenated promoter content is kept between 10 and 20%, and the partial carbon monoxide pressure is 40-200 bar. Said method enables both the rate of carbonylation and the acetic acid selectivity to be increased.