Abstract:
Preparing a primary amine by alcohol amination of alcohol with ammonia and elimination of water includes reacting, in a homogeneously catalyzed reaction, a mixture of alcohol, ammonia, nonpolar solvent, and catalyst, in a liquid phase, to obtain a product mixture. The process then includes phase separating the product mixture into a polar product phase and a nonpolar product phase, and separating off the nonpolar product phase. At least some of the nonpolar phase returns to the homogenously catalyzed reaction. The process further includes separating off amination product from the polar product phase. At least some of the catalyst is in the nonpolar phase, and the catalyst accumulates in the nonpolar phase.
Abstract:
The invention relates to a method for producing 2-keto-L-gulonic acid-C4–C10 alkyl ester by esterifying 2-keto-L-gulonic acid (KGS) with an unsaturated, branched or unbranched C4–C10 alcohol. The inventive method is characterized by the fact that an aqueous KGS solution is reacted with a C4–C10 alcohol up to an esterification degree of 20 to 70 percent in a pre-esterification process carried out under acidic catalysis conditions; and the obtained product is dehydrogenated with an unsaturated, branched or unbranched C4–C10 alcohol in a continuous rectification device, whereby the esterification reaction continues, n-butanol preferably being used as the alkyl alcohol. In a preferred embodiment, the aqueous KGS solution is concentrated up to or beyond the limit of solubility prior to the esterification process, preferably by catalyzing a homogeneous or heterogeneous catalyst, especially sulfonic acid, at temperatures of 50 to 120° C. In another embodiment, the produced KGS ester is reacted in one or several additional steps so as to obtain L-ascorbic acid.
Abstract:
A material useful as catalyst for the hydrogenation of alpha, omega-dinitriles comprises (a) iron or a compound based on iron or mixtures thereof, (b) from 0.001 to 0.3% by weight based on (a) of a promoter based on 2, 3, 4 or 5 elements selected from the group consisting of aluminum, silicon, zirconium, titanium and vanadium, (c) from 0 to 0.3% by weight based on (a) of a compound based on an alkali and/or alkaline earth metal, and also (d) from 0.001 to 1% by weight based on (a) of manganese.
Abstract:
Passivated iron useful as catalytically active component after activation is activated by hydrogen at elevated temperature and elevated pressure in the presence of a nitrile.
Abstract:
A process for the coproduction of 6-aminocapronitrile and hexamethylenediamine starting from adiponitrile by a) hydrogenating adiponitrile in the presence of a catalyst comprising an element of the eighth transition group as catalytically active component, to obtain a mixture comprising 6-aminocapronitrile, hexamethylenediamine, adiponitrile and high boilers, b) distillatively removing hexamethylenediamine from the mixture comprising 6-aminocapronitrile, hexamethylenediamine, adiponitrile and high boilers, and either c1) distillatively removing 6-aminocapronitrile, and then d1) distillatively removing adiponitrile, or c2) simultaneously distillatively removing 6-aminocapronitrile and adiponitrile into separate fractions is characterized by base of column temperatures below 185° C. in steps d1) or c2).
Abstract:
A process for hydrogenation of aliphatic alpha, omega-dinitriles in the presence of a heterogeneous fixed bed catalyst comprises using a reaction mixture comprising from 2 &mgr;mol to 30 mmol NA, K, Rb, Cs, Mg, Ca, Sr, Ba or Mn or mixtures thereof in the form of a basic salt, based on 10 mol of aliphatic alpha, omega-dinitrile used.
Abstract:
Process for preparing alkanolamines which have a primary amino group (—NH2) and a hydroxyl group (—OH) by alcohol amination of diols having two hydroxyl groups (—OH) by means of ammonia with elimination of water, wherein the reaction is carried out homogeneously catalyzed in the presence of at least one complex catalyst comprising at least one element selected from groups 8, 9 and 10 of the Periodic Table and also at least one donor ligand.
Abstract:
Process for the preparation of primary amines which have at least one functional group of the formula (—CH2—NH2) by alcohol amination of starting materials which have at least one functional group of the formula (—CH2—OH), with ammonia, with the elimination of water, where the alcohol amination is carried out under homogeneous catalysis in the presence of at least one complex catalyst which comprises at least one element selected from groups 8 and 9 of the Periodic Table of the Elements, and also at least one phosphorus donor ligand of the general formula (I).
Abstract:
The invention relates to a method for producing 2-keto-L-gulonic acid-C4-C10 alkyl ester by esterifying 2-keto-L-gulonic acid (KGS) with an unsaturated, branched or unbranched C4-C10 alcohol. The inventive method is characterized by the fact that an aqueous KGS solution is reacted with a C4-C10 alcohol up to an esterification degree of 20 to 70 percent in a pre-esterification process carried out under acidic catalysis conditions; and the obtained product is dehydrogenated with an unsaturated, branched or unbranched C4-C10 alcohol in a continuous rectification device, whereby the esterification reaction continues, n-butanol preferably being used as the alkyl alcohol. In a preferred embodiment, the aqueous KGS solution is concentrated up to or beyond the limit of solubility prior to the esterification process, preferably by catalyzing a homogeneous or heterogeneous catalyst, especially sulfonic acid, at temperatures of 50 to 120 ° C. In another embodiment, the produced KGS ester is reacted in one or several additional steps so as to obtain L-ascorbic acid.
Abstract:
Nitriles are hydrogenated to primary amines over an activated, alpha-Al2O3-containing, macroporous Raney catalyst based on an alloy of aluminum and at least one transition metal selected from the group consisting of iron, cobalt and nickel, and, if desired, one or more further transition metals selected from the group consisting of titanium, zirconium, chromium and manganese, which is obtainable by a process comprising the steps in the order (a)-(f): (a) preparing a kneadable composition comprising the alloy, a shaping aid, water and a pore former; (b) shaping the kneadable composition to form a shaped body; (c) calcining the shaped body; (d) activating the calcined shaped body by treatment with aqueous alkali metal hydroxide solution; (e) rinsing the shaped catalyst body with aqueous alkali metal hydroxide solution; (f) rinsing the shaped catalyst body with water.
Abstract translation:基于铝和至少一种选自铁,钴和镍的过渡金属的合金,并且如果需要,腈在一种活化的含α-Al 2 O 3的大孔阮内催化剂上氢化成伯胺,如果需要, (a) - (f):(a)制备包含该合金的可捏合组合物的方法可以获得更多的选自钛,锆,铬和锰的过渡金属, 成型助剂,水和成孔剂;(b)使捏合组合物成形以形成成形体;(c)煅烧成形体;(d)用碱金属氢氧化物水溶液处理活化煅烧成形体;(e) 用碱金属氢氧化物水溶液冲洗成型的催化剂体;(f)用水冲洗成型的催化剂体。