Ciba Specialty Chemicals Corporation

Martina Hoffmann

Holger Lautenbach

Jacek Malisz

Rainer Kaufel

Elke Polley

Adolf Käser

Adolf K&auml;ser

Klaus Nussbaum

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 &#x3bc;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.

Process for preparing solutions of anionic organic compounds

There is described the preparation of phenylphenol compounds of formula ( ) by reaction of a keto compound of formula ( ) with dioxolane of formula ( ) and with an ammonium compound of formula ( ) to from &bgr;-aminoketone compound of formula ( ) (reaction step (I)), reaction of the compound of formula ( ) with a compound of formula ( ) to form a compound of formula ( ) (reaction step (II)), and subsequent alkylation to form a compound of formula ( ) (reaction step (III)) in accordance with scheme (A); wherein R , R , R , R and R are each independently of the others hydrogen or C -C alkyl; R , R and R are each independently of the others hydrogen or C -C alkyl; ant Hal is a halogen atom. The compounds prepared in accordance with the invention are suitable as antimicrobial active substances.

Process for the preparation of phenylphenol compounds

Process for the preparation of solutions of anionic organic compounds

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Hausen, Germany

Martina Hoffmann