Abstract: The invention relates to a process for preparing 1,3-butadiene by means of ene-yne metathesis over at least one transition metal catalyst of the element ruthenium.

Abstract: The invention relates to a process for preparing 1,3-butadiene by means of ene-yne metathesis over at least one transition metal catalyst of the element ruthenium.

Abstract: Described is a process for preparing concentrated solutions or suspensions of anionic organic compounds which comprises a) acidifying an aqueous solution or suspension of an anionic organic compound containing salts and/or impurities to a pH of 4.5 or less, if the pH is above this value, so that b) the anionic organic compound is water-insoluble and precipitates in the form of the free acid, c) bringing the suspension to a salt content below 2% by weight, based on the total weight of the retentate, by means of ultrafiltration with a membrane having pore diameters of from 0.001 to 0.02 ?m, and d) optionally washing out the salts with water having a pH below 4,5, e) optionally carrying out acid-free washing with water thereafter, and then f) concentrating, so that the amount of anionic organic compound is 5-50% by weight, and g) if desired, bringing the anionic organic compound into solution by adding an appropriate base.

Abstract: There is described the preparation of phenylphenol compounds of formula (1) by reaction of a keto compound of formula (3) with dioxolane of formula (4) and with an ammonium compound of formula (5) to from &bgr;-aminoketone compound of formula (6) (reaction step (I)), reaction of the compound of formula (6) with a compound of formula (7) to form a compound of formula (2) (reaction step (II)), and subsequent alkylation to form a compound of formula (1) (reaction step (III)) in accordance with scheme (A); wherein R1, R2, R3, R6 and R7 are each independently of the others hydrogen or C1-C8alkyl; R4, R5 and R8 are each independently of the others hydrogen or C1-C5alkyl; ant Hal is a halogen atom. The compounds prepared in accordance with the invention are suitable as antimicrobial active substances.

Abstract: A process for the preparation of concentrated solutions or suspensions of anionic organic compounds is described, which process comprises a) acidifying an aqueous solution or dispersion of an anionic organic compound that comprises salts and/or impurities to a pH of 4.5 or less, if the pH is above that value, so that the anionic organic compound becomes insoluble in water and precipitates out in the form of the free acid, b) bringing the suspension obtained from the previous step to a salt content below 2% by weight, based on the total weight of retentate, by means of ultra-filtration with a ceramic membrane or an acid-resistant organic membrane having a pore size of from 1 to 20 nm, and c) optionally washing out of the salts with water at a pH of less than 4.

Abstract: There is described the preparation of phenylphenol compounds of formula (I) by reaction of a keto compound of formula (3) with dioxolane of formula (4) and with an ammonium compound of formula (5) to form a &bgr;-aminoketone compound of formula (6) (reaction step (I)), reaction of the compound of formula (6) with a compound of formula (7) to form a compound of formula (2) (reaction step (II)), and subsequent alkylation to form a compound of formula (I) (reaction step (III)) in accordance with scheme (A); wherein R1, R2, R3, R6 and R7 are each independently of the others hydrogen or C1-C8-alkyl; R4, R5 and R8 are each independently of the others hydrogen or C1-C5alkyl; and Hal is a halogen atom. The compounds prepared in accordance with the invention are suitable as antimicrobial active substances.

Abstract: Described is a process for preparing concentrated solutions or suspensions of anionic organic compounds which comprises a) acidifying an aqueous solution or suspension of an anionic organic compound containing salts and/or impurities to a pH of 4.5 or less, if the pH is above this value, so that b) the anionic organic compound is water-insoluble and precipitates in the form of the free acid, c) bringing the suspension to a salt content below 2% by weight, based on the total weight of the retentate, by means of ultrafiltration with a membrane having pore diameters of from 0.001 to 0.02 &mgr;m, and d) optionally washing out the salts with water having a pH below 4,5, e) optionally carrying out acid-free washing with water thereafter, and then f) concentrating, so that the amount of anionic organic compound is 5-50% by weight, and g) if desired, bringing the anionic organic compound into solution by adding an appropriate base.