摘要:
Process for the selective hydrogenation of alphatic or aromatic substrates under supercritical or near critical conditions. Hydrogenation is effected using a heterogeneous catalyst in a continuous flow reactor containing a supercritical or near critical reaction medium and selectively of product formation is achieved by varying one or more of the temperature, pressure, catalyst and flow rate.
摘要:
Aliphatic alkanals with a water content of greater than 300 ppm which are stable in storage, and a method of improving the storage stability of these aliphatic alkanals, especially of substituted, sulfur-containing alkanals. The formation of oligomers, polymers and condensation products from elimination reactions and oxidation and the subsequent reactions of the products formed results in undesired impurities that are largely prevented by the addition of an organic acid that forms metal complexes and, optionally, alkanolamines or trialkanolamines.
摘要:
This invention relates to a process for the production of a homogeneously waterproofed concrete (integrally waterproofed concrete) in which an aqueous hydrolysable, emulsion containing organosilicon compounds is added before curing to the fresh concrete mix prepared from water, inorganic and optionally organic constituents, which emulsion contains at least one alkoxysilane and optionally an organosilicon compound acting as a surfactant.
摘要:
Preparation of 2,3,5-trimethylhydroquinone diesters by rearrangement of 2,6,6-trimethylcyclohex-2-ene-1,4-dione (4-oxo-isophorone, ketoisophorone) in the presence of a solid, acid catalyst and an acylating agent, for example carboxylic acid anhydrides or carboxylic acid halides. The 2,3,5-trimethylhydroquinone diester may then optionally be saponified to the free 2,3,5-trimethylhydroquinone, which is a valuable building block in the synthesis of vitamin E.
摘要:
The invention concerns a method of producing oxazolidinones of formula (I), wherein R.sup.1 -R.sup.5 have the meanings given in the description, by reacting cyclical anhydrides of formula (II) with carbonyl compounds of general formula (III) at temperatures between ambient temperature and approximately 150.degree. C. The invention also concerns the production of the cyclical anhydrides of formula (II) by reacting N-protected aminodicarboxylic acids of formula (IV) with a dehydrating agent in situ. The invention further concerns the use of oxazolidinones of formula (I) for the .alpha.-selective production of esters of formula (V) and amides of general formula (VII).
摘要:
A supported catalyst includes: a) 0.5-15 wt. % of one or more Cu-II compounds, the quantitative amounts referring to copper metal; b) 0.1-8 wt. % of one or more alkali metal compounds, the quantitative amounts referring to alkali metal; c) 0.1-10 wt. % of an oxide mixture including; c1) 80-95 mole % of oxides of cerite rare earths with atomic Nos. 57 to 62, except promethium, and c2) 5-20 mole % of zirconium dioxide, where c1) and c2) must together total 100 mole % and the quantitative amount of c) refers to the oxides of the mixture, and d) the remainder up to 100 wt. % being .gamma. and/or .alpha.-aluminum oxide as support material, wherein e) the support material d) has a total pore volume in the range from 0.65 to 1.2 cm.sup.3 /g, and wherein f) the supported catalyst is present in the form of cylindrical hollow bodies having at least one passage channel, the ratio of height h to external diameter d.sup.e being less than 1.5 for diameters d.sub.e of up to 6 mm, and the ratio h/d.sub.e being less than 0.6 for diameter d.sub.e greater than 6 mm. A process for producing the supported catalyst is also described.
摘要:
A process for the direct preparation of alkali metal cyanide and alkaline earth metal cyanide granules from an HCN-containing gas and an aqueous solution or suspension of an alkali metal or alkaline earth metal hydroxide. The reaction is performed in a reactor for fluidized bed spray granulation, wherein a solution or suspension of the hydroxide is sprayed onto seed granules of the cyanide being prepared and at the same time a hydrogen cyanide-containing gas is supplied to the reactor and water is evaporated by means of a fluidizing gas. The preferred fluidizing gas is steam. The reaction gases from a BMA or Andrussow process may be quenched with water and the gas mixture used as fluidizing gas. By using a CO.sub.2 -free HCN-containing gas, alkali metal cyanide granules with advantageous properties, including a combined concentration of alkali metal carbonate and alkali metal formate of less then 0.4 wt. %, are obtainable.
摘要:
The invention relates to an isolated polynucleotide from coryneform bacteria, comprising a polynucleotide sequence chosen from the group consisting of a) polynucleotide which is identical to the extent of at least 70% to a polynucleotide which codes for a polypeptide which comprises the amino acid sequences of SEQ ID NO. 2 or SEQ ID NO. 4, b) polynucleotide which codes for a polypeptide which comprises an amino acid sequence which is identical to the extent of at least 70% to the amino acid sequences of SEQ ID NO. 2 or SEQ ID NO. 4 c) polynucleotide which is complementary to the polynucleotides of a) or b) and d) polynucleotide comprising at least 15 successive nucleotides of the polynucleotide sequences of a), b) or c) and a process for the preparation of L-amino acids, which comprises carrying out the following steps: a) fermentation of the desired L-amino acid-producing bacteria in which at least the tal gene is amplified, b) concentration of the desired product in the medium or in the cells of the bacteria and c) isolation of the L-amino acid.
摘要翻译:本发明涉及来自棒状细菌的分离的多核苷酸,其包含选自以下的多核苷酸序列:a)与编码多肽的多核苷酸的程度相同的多核苷酸,所述多核苷酸包含氨基酸序列 SEQ ID NO: 2或SEQ ID NO。 4,b)编码多肽的多核苷酸,其包含与SEQ ID NO:1的氨基酸序列至少70%的程度相同的氨基酸序列。 2或SEQ ID NO。 4)与a)或b)的多核苷酸互补的多核苷酸和d)包含a),b)或c)的多核苷酸序列的至少15个连续核苷酸的多核苷酸,以及制备L-氨基酸的方法 其包括进行以下步骤:a)发酵所需的L-氨基酸生产细菌,其中至少有tal基因被扩增,b)所需产物在培养基中或细菌中的浓度,以及 c)分离L-氨基酸。
摘要:
The invention relates to preferably recombinant DNA derived from Corynebacterium and replicable in coryneform microorganisms, which contains at least one nucleotide sequence that codes for the thrE gene, and a process for the production of L-threonine, which is characterised in that the following steps are carried out: a) Fermentation of microorganisms in which at least the thrE gene is amplified (overexpressed), optionally in combination with further genes, b) Enrichment of the L-threonine in the medium or in the cells of the microorganisms, and c) Isolation of the L-threonine.
摘要:
Raney copper which is doped with at least one metal from the group comprising iron and/or noble metals is used as a catalyst in the dehydrogenation of alcohols.