摘要:
What is proposed is a process for preparing aminopolycarboxylates proceeding from the corresponding polyalkanolamines by oxidative dehydrogenation in the presence of a catalyst comprising 1 to 90% by weight of copper, based on the total weight of the catalyst, using a base, which comprises first performing a partial conversion of the polyalkanolamine to a reaction mixture comprising the aminopolycarboxylate at a temperature in the range from 140 to 180° C. until at least 10 to 90 mol % of the polyalkanolamine has been depleted, and then continuing the conversion at elevated temperature.
摘要:
A process is proposed for preparing isocyanates by thermally cleaving carbamates to obtain a carbamate cleavage gas comprising the corresponding isocyanate and the corresponding alcohol, which comprises quenching the carbamate cleavage gas in the presence of an ether which functions as an inhibitor for the reverse reaction of the isocyanate with the alcohol.
摘要:
The invention relates to a process for the preparation of formamides by reacting aromatic amines with a formic acid ester in the presence of a catalyst, wherein the catalyst is a phosphorus-containing acid or a Lewis-acidic metal salt.
摘要:
A process for preparing aminopolycarboxylates proceeding from the corresponding polyalkanolamines by oxidative dehydrogenation in the presence of a catalyst comprising 1 to 90% by weight of copper, based on the total weight of the catalyst, using a base, which comprises first performing a partial conversion of the polyalkanolamine to a reaction mixture comprising the aminopolycarboxylate at a temperature in the range from 140 to 180° C. until at least 10 to 90 mol% of the polyalkanolamine has been depleted, and then continuing the conversion at elevated temperature.
摘要:
Proposed is a process for preparing isocyanates by dissociating the corresponding carbamates, which comprises dissociating the carbamates in the presence of a heterogeneous Lewis-acidic catalyst.
摘要:
The present invention relates to a process for preparing aminocarboxylates, proceeding from amines, by employing a reaction sequence composed of ethoxylation to amino alcohols and subsequent oxidative dehydrogenation to the corresponding aminocarboxylates, especially the alkali metal or alkaline earth metal salts of the complexing agents MGDA (methylglycinediacetic acid), EDTA (ethylenediaminetetra-acetic acid) and GLDA (glutamic acid diacetic acid) or the free acids thereof.
摘要:
A process for preparing urethanes by reacting aromatic diamines with a dialkyl carbonate, wherein the alkyl radical of the organic dialkyl carbonate comprises 2-18 carbon atoms and one or more heteroatoms and the reaction is performed in the presence of a catalyst.
摘要:
A process is proposed for preparing isocyanates by thermally cleaving carbamates to obtain a carbamate cleavage gas comprising the corresponding isocyanate and the corresponding alcohol, which comprises quenching the carbamate cleavage gas in the presence of an ether which functions as an inhibitor for the reverse reaction of the isocyanate with the alcohol.
摘要:
The invention relates to a process for obtaining a dialkyl carbonate and an alkylene glycol from a stream comprising dialkyl carbonate, alkylene carbonate, alkylene glycol and alcohol, comprising the following steps: (a) distillatively removing a stream (5) comprising dialkyl carbonate and alkylene glycol as a heteroazeotrope from the stream comprising dialkyl carbonate, alkylene carbonate, alkylene glycol and alcohol in a first distillation stage (1), (b) separating the stream (5) comprising dialkyl carbonate and alkylene glycol as a heteroazeotrope into a first crude product stream (27) comprising essentially di-alkyl carbonate and a second crude product stream (29) comprising essentially alkylene glycol in an apparatus for phase separation (25).
摘要:
The content of the invention is a process for preparing urethanes by reaction of aromatic amines with a dialkyl carbonate, wherein the alkyl radical of the organic dialkyl carbonate comprises 4-18 carbon atoms and is branched in the 2 position, and the reaction is performed in the presence of a substoichiometric amount of base, based on the amino groups.