Abstract: The invention relates in particular to a process for the preparation of DL/LD-methionine diketopiperazine (I) characterized in that a DD/LL-methionylmethionine-containing aqueous solution or suspension, which has a pH of 3 to 7, measured using a pH electrode at 20° C., is reacted at a temperature of 150 to 220° C., preferably at 170 to 210° C., until an aqueous solution or suspension has formed containing at least a proportion of 30 mol %, preferably 50 mol %, especially 60 mol % of DL/LD-methionine diketopiperazine, based on the total content of DL/LD- and DD/LL-methionine diketopiperazine in the reaction mixture. This process forms part of an overall process for the preparation of DL/LD-methionylmethionine, which is obtained by hydrolysis from the DL/LD-methionine diketopiperazine (I) produced initially.

Abstract: The invention relates to a process for preparing 2,6-bis(methionyl)-1,4-dketopiperazine, comprising the following steps: a) heating a reaction mixture comprising methionine and polar protic solvent at a temperature of less than 170.0° C., while passing an inert gas stream over or through the reaction mixture; b) obtaining 2,6-bis(methionyl)-1,4-diketopiperazine.

Abstract: Improved process for working up diacetone acrylamide solutions, obtained by reaction of acetone or diacetone alcohol with acrylonitrile and sulfuric acid and subsequent dilution and neutralization, in which a) the organic phase obtained subsequent to the neutralization, which comprises the crude diacetone acrylamide, is hydrolyzed by addition of an aqueous alkaline solution in order to remove acrylamide, then b) after phase separation has been carried out, the organic phase, which comprises the crude diacetone acrylamide, is neutralized by addition of an acid, and c) in succession, low-boiling-point byproducts are removed by distillation in the presence of one or more polymerization inhibitors, then t-butylacrylamide is removed by distillation and, finally, the diacetone acrylamide is isolated by product distillation, and d) the diacetone acrylamide thus obtained is converted into its final form.

Abstract: A process for the continuous production of a compound of Formula (II), HO—R1—ONO2 (II) wherein R1 is a straight chain alkyl radical having from 3 to 6 carbon atoms, in a two-phase solvent system, comprising contacting a compound of Formula (I), HO—R1—OH (I) wherein R1 is as defined above, with nitric acid in the presence of a first solvent, wherein the compound of Formula (II) is continuously extracted into a second solvent, and the reaction is carried out in a mixing microreactor which provides a power loss of at least 1.3 times the power loss provided under identical conditions by a circular cross-section straight-channel microreactor having an internal diameter equal to the average hydraulic diameter of the mixing microreactor and a length equal to the length of the mixing microreactor.

Abstract: A process for the preparation of a cyclopropane derivative of Formula (I), by reacting an olefin of Formula (II), with a carbene of the formula:CR1R2, in a reaction vessel, optionally in the presence of a solvent, wherein, R1 and R2 are each independently hydrogen, C1-C6 alkyl, C2-C6 alkenyl, aryl, heteroaryl, heterocyclyl, carbocyclyl, heterocyclyl, —C(O)R7 or —NR82; R3, R4, R5 and R6 are each independently hydrogen, C1-C6 alkyl, C1-C6 alkoxy, C2-C6 alkenyl, aryl, aryloxy, heteroaryl, heterocyclyl, carbocyclyl, heterocyclyl, —C(O)R9, —NR102, —SR11, —S(O)R11, or —SO2R11, or R3 and R6 are as defined above and R4 and R5 together form a ring, which ring is carbocyclyl, heterocyclyl, aromatic or heteroaromatic; R7 is hydrogen, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, aryl, aryloxy, heteroaryl or —NR102; R8 is hydrogen, C1-C6 alkyl, C1-C6 alkenyl, aryl, heteroaryl, carbocyclyl or heterocyclyl; R9 is hydrogen, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, aryl, aryloxy or heteroaryl; R10 is hydrogen, C1-C6 alkyl, C2-C6 alkenyl, a

Abstract: A tube bundle falling film microreactor for performing gas-liquid reactions, which has: a) at least one vertical tube with b) a device for distributing the liquid on the inside of the tube and c) a liquid collecting system, and d) a device for gas supply and removal, and use thereof.

Abstract: A process for the preparation of a cyclopropane derivative of Formula (I), by reacting an olefin of Formula (II), with a carbene of the formula: CR1R2, in a reaction vessel, optionally in the presence of a solvent, wherein, R1 and R2 are each independently hydrogen, C1-C6 alkyl, C2-C6 alkenyl, aryl, heteroaryl, heterocyclyl, carbocyclyl, heterocyclyl, —C(O)R7 or —NR82; R3, R4, R5 and R6 are each independently hydrogen, C1-C6 alkyl, C1-C6 alkoxy, C2-C6 alkenyl, aryl, aryloxy, heteroaryl, heterocyclyl, carbocyclyl, heterocyclyl, —C(O)R9, —NR102, —SR11, —S(O)R11, or —SO2R11, or R3 and R6 are as defined above and R4 and R5 together form a ring, which ring is carbocyclyl, heterocyclyl, aromatic or heteroaromatic; R7 is hydrogen, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, aryl, aryloxy, heteroaryl or —NR102; R8 is hydrogen, C1-C6 alkyl, C1-C6 alkenyl, aryl, heteroaryl, carbocyclyl or heterocyclyl; R9 is hydrogen, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, aryl, aryloxy or heteroaryl; R10 is hydrogen, C1-C6 alkyl, C2-C6 alkenyl,

Abstract: A process for the continuous production of a compound of Formula (II), HO—R1—ONO2 (II) wherein R1 is a straight chain alkyl radical having from 3 to 6 carbon atoms, in a two-phase solvent system, comprising contacting a compound of Formula (I), HO—R1—OH (I) wherein R1 is as defined above, with nitric acid in the presence of a first solvent, wherein the compound of Formula (II) is continuously extracted into a second solvent, and the reaction is carried out in a mixing microreactor which provides a power loss of at least 1.3 times the power loss provided under identical conditions by a circular cross-section straight-channel microreactor having an internal diameter equal to the average hydraulic diameter of the mixing microreactor and a length equal to the length of the mixing microreactor.

Abstract: Improved process for working up diacetone acrylamide solutions, obtained by reaction of acetone or diacetone alcohol with acrylonitrile and sulfuric acid and subsequent dilution and neutralization, in which a) the organic phase obtained subsequent to the neutralization, which comprises the crude diacetone acrylamide, is hydrolyzed by addition of an aqueous alkaline solution in order to remove acrylamide, then b) after phase separation has been carried out, the organic phase, which comprises the crude diacetone acrylamide, is neutralized by addition of an acid, and c) in succession, low-boiling-point byproducts are removed by distillation in the presence of one or more polymerization inhibitors, then t-butylacrylamide is removed by distillation and, finally, the diacetone acrylamide is isolated by product distillation, and d) the diacetone acrylamide thus obtained is converted into its final form

Abstract: A tube bundle falling film microreactor for performing gas-liquid reactions, which has: a) at least one vertical tube with b) a device for distributing the liquid on the inside of the tube and c) a liquid collecting system, and d) a device for gas supply and removal, and use thereof.

Abstract: Reaction plates for microreactors for performing gas-liquid reactions, which consist of falling-film plates with a surface which has a randomly distributed, unordered fine structure or microstructure.