摘要:
A method for isolating methylglycinenitrile-N,N-diacetonitrile (MGDN) from an aqueous mixture comprising MGDN is provided The method comprises cooling the aqueous mixture in one or more steps In one of these steps the mixture is cooled at a cooling rate of at least 20 K/h from a temperature above the solidification point of MGDN to a temperature below the solidification point of MGDN The method is implemented continuously
摘要:
The present invention relates to a method for the production of aminodicarboxylic acid-N,N,diacetic acids of the general Formula I, wherein X independently of one another represents hydrogen or an alkali metal and n represents a number 1 or 2. Furthermore, the invention relates to aminodicarboxylic acid-N,N-diacetic acids of high purity. The inventive method comprises the following steps: A.) reacting an aminodicarboxylic acid of the general Formula II, wherein X and n have the aforementioned meanings, with 0.8 to 1.2 mole equivalents of formaldehyde and with 0.8 to 1.2 mole equivalents of hydrocyanic acid; b) reacting the reaction products of step a) with 0.8 to 1.2 mole equivalents of hydrocyanic acid and with 0.8 to 1.2 mole equivalents of formaldehyde; c) hydrolyzing in the reaction product obtained in step b).
摘要:
In a process for preparing isocyanates by reacting the corresponding primary amines with phosgene in an inert solvent, use is made of from 0.01 to 50 mol % of a sulfonamide, based on the total amount of primary amine and isocyanate formed in the reaction solution.
摘要:
The invention relates to a method for producing o-choromethyl benzenecarbonyl chlorides of formula (I), wherein R1-R4 can be the same or different and stand for hydrogen, C1-C4-alkyl, halogen or trifluoromnethyl, by converting benzocondensed lactones of formula (II), wherein R1-R4 have the aforementioned meaning, with gaseous or liquid phosgene and the dimers or trimers thereof. The inventive method is characterized in that the conversion is carried out in the presence of catalytical amounts of a Lewis acid and catalytical amounts of a phosgenation catalyst
摘要:
Carbonyldiimidazoles of the formulae Ia, Ib, Ic or mixtures thereof where R1 is C1-4-alkyl and R2 is hydrogen or methyl, and tert-butyl esters derived therefrom are described.
摘要:
The present invention provides process for the preparation of chlorocarbonyl chlorides of the formula I R1—CHCl—Y—COCl (I), where R1 is for example hydrogen or C1- to C20-alkyl and Y is for example a saturated or mono- or polyolefinically unsaturated C2-C8-alkylene chain, by reacting lactones with a chlorinating agent in the presence of a urea compound.
摘要:
The invention relates to a process for preparing low-by-product, light-color methylglycine-N,N-diacetic acid tri(alkali metal) salt by alkaline hydrolysis of methylglycinediacetonitrile (MGDN), comprising the steps in the sequence (a) to (f): (a) mixing of MGDN with aqueous alkali at a temperature of ≦30° C.; (b) allowing the aqueous alkaline MGDN suspension to react at a temperature in the range from 10 to 30° C. over a period of from 0.1 to 10 h to form a solution; (c) allowing the solution from step (b) to react at a temperature in the range from 30 to 40° C. over a period of from 0.1 to 10 h; (d) optionally allowing the solution from step (c) to react at a temperature in the range from 50 to 80° C. over a period of from 0.5 to 2 h; (e) optionally allowing the solution from step (c) or (d) to react at a temperature in the range from 110 to 200° C. over a period of from 5 to 60 min; (f) hydrolysis and removal of ammonia of the solution obtained in step (c), (d) or (e) by stripping at a temperature of from 90 to 105° C.
摘要:
The invention relates to a process for preparing low-by-product, light-color methylglycine-N,N-diacetic acid tri(alkali metal) salt by alkaline hydrolysis of methylglycinediacetonitrile (MGDN), comprising the steps in the sequence (a) to (f): (a) mixing of MGDN with aqueous alkali at a temperature of ≦30° C.; (b) allowing the aqueous alkaline MGDN suspension to react at a temperature in the range from 10 to 30° C. over a period of from 0.1 to 10 h to form a solution; (c) allowing the solution from step (b) to react at a temperature in the range from 30 to 40° C. over a period of from 0.1 to 10 h; (d) optionally allowing the solution from step (c) to react at a temperature in the range from 50 to 80° C. over a period of from 0.5 to 2 h; (e) optionally allowing the solution from step (c) or (d) to react at a temperature in the range from 110 to 200° C. over a period of from 5 to 60 min; (f) hydrolysis and removal of ammonia of the solution obtained in step (c), (d) or (e) by stripping at a temperature of from 90 to 105° C.
摘要:
A method is provided for the intrinsically safe handling of 3-chloropropyne in the presence of a diluent with a boiling point ranging from −50° C. (223 K) to 200° C. (473 K) under atmospheric pressure, wherein the concentration of 3-chloropropyne in the liquid phase and in the gas phase is kept below the concentrations capable of deflagration by means of the type and amount of the diluent, the temperature and the total system pressure, together with the use of a 3-chloropropyne prepared, stored or transported in this way in the synthesis of dyestuffs, pharmaceutical and agricultural active ingredients, electroplating auxiliaries, disinfectants, steroids and growth hormones.
摘要:
Process for the purification of carbonyl chlorides which have been prepared by reacting carboxylic acids with phosgene or thionyl chloride in the presence of a catalyst adduct, in which the carbonyl chlorides are treated with a hydrohalide of carboxamides of the formula (I) in which R1 is hydrogen or C1- to C3-alkyl; R2 and R3 independently of one another are C1- to C4-alkyl, or R2 and R3 together are a C4- or C5-alkylene chain, and the carbonyl chloride purified in this way is isolated by separation off from the carboxamide hydrohalide phase.