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 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.
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:
An iridium-based solution is prepared by contacting components in a liquid phase containing (a) a carbonylated iridium compound, (b) hydriodic acid, a precursor of such an acid, or mixture thereof, and (c) a solvent; under a total pressure of between 1 and 10 bar at a temperature not greater than the boiling temperature of the solvent under conditions in which the components are brought into contact. The iridium-based solution can be used as a catalyst for carrying out carbonylation, hydroformylation or isomerization reactions.
摘要:
Hydroxylated aromatic compounds devoid of substituents in the para-position to the hydroxyl group thereof are para-hydroxyalkylated, e.g., into optionally substituted p-hydroxymandelic acid compounds, more particularly p-hydroxymandelic acid and 3-methoxy-p-hydroxymandelic acid, by condensing same with an organic carbonyl compound in the presence of a quaternary ammonium hydroxide.