摘要:
The present invention provides a process for preparing 1,6-hexanediol having a purity of ≧99.5% by weight by catalytically dimerizing acrylic esters and catalytically hydrogenating the hexenedioic diesters obtained in this way to 1,6-hexanediol by a) dimerizing C1- to C8-acrylic esters in the presence of at least one rhodium compound to give mixtures of predominantly 2- and 3-hexenedioic diesters, b) hydrogenating the resulting dimerizing effluent in the presence of chromium-free catalysts comprising predominantly copper as the hydrogenation component and c) purifying the crude 1,6-hexanediol obtained in this way by fractional distillation.
摘要:
A process for continuously preparing a compound which bears at least two functional groups which are each independently selected from the group consisting of nitrile group, carboxylic acid group, carboxylic ester group and carboxamide group.
摘要:
Disclosed is a method for jointly producing (i) formic acid (III); (ii) a carboxylic acid comprising at least two carbon atoms (II) and/or the derivatives thereof; and (iii) a carboxylic acid anhydride (VII). According to said method, (a) a formic acid ester (I) is transesterfied to formic acid (III) and the corresponding carboxylic acid ester (IV) by means of a carboxylic acid comprising at least two carbon atoms (II); (b) at least one portion of the carboxylic acid ester (IV) formed in step (a) is carbonylated in order to obtain the carboxylic acid anhydride (V); and (c) at least one portion of the carboxylic acid anhydride (V) formed in step (b) is further dehydrated by means of a carboxylic acid (VI) so as to form a carboxylic acid anhydride (VII) and the carboxylic acid (II).
摘要:
Formic acid and a carboxylic acid having at least two carbon atoms and/or derivatives thereof are prepared jointly by a process in which (a) a formic ester (I) is transesterified with a carboxylic acid having at least two carbon atoms (II) to form formic acid (III) and the corresponding carboxylic ester (IV); and (b) at least part of the carboxylic ester (IV) formed in step (a) is carbonylated to give the corresponding carboxylic anhydride (V).