Abstract: The present invention relates to a process for the preparation of N-phosphonomethyliminodiacetic acid by reacting an alkali metal salt of iminodiacetic acid with phosphorus trichloride in aqueous solution with formation of the hydrochloride of iminodiacetic acid, phosphorous acid and of the corresponding alkali metal chloride, followed by reaction with a formaldehyde source and, if desired, recovery of the N-phosphonomethyliminodiacetic acid from the reaction mixture, in which water, which may comprise HCl, is removed from the reaction mixture during and/or after reacting the alkali metal salt of iminodiacetic acid with phosphorus trichloride until the concentration of iminodiacetic acid hydrochloride is at least 40% by weight, based on the weight of the reaction mixture minus the weight of alkali metal chloride. The process makes possible the preparation of N-phosphonomethyliminodiacetic acid in a simple fashion and in high yield.

Abstract: The invention relates to a method for producing the tautomeric form (I) of 2,4,6-trianilino-p-(carbo-2?-ethylhexyl-1?-oxy)-1,3,5-triazine by the crystallization of a tautoner mixture in the presence of one or more solvents selected from the group consisting of aliphatic alcohol having 2 8 C-atoms made of aliphatic alcohol, aliphatic carboxylic acid alkyl esters having a total of between 3–10 C-atoms, aromatic carboxylic acid alkyl esters having a total of between 8–12 C-atoms, aliphatic carboxylic acid esters having a total of between 3 9 C-atoms, carboxylic acid nitriles having a total of between 2–8 C-atoms, dialkylketones having a total of between 3–6 C-atoms and aliphatic sulphones having a total of between 3–6 C-atoms. The solvent or solvent mixture can additionally contain up to 30 wt % of a hydrocarbon (I) acts as a light protecting agent in cosmetic preparations.

Abstract: Described is a process for the preparation of a particulate tetrahydro-3,5-dimethyl-1,3,5-thiadiazine-2-thione product by combining a first aqueous solution comprising methylammonium N-methyldithiocarbamate with a second aqueous solution comprising formaldehyde, followed by separation and drying of the resulting solid, which comprises combining the first and the second aqueous solutions in such a way that the ratio between the concentrations of dithiocarbamate functions and of formaldehyde is essentially constant in the reaction mixture over time during the duration of the reaction.

Abstract: 4,4-Diarylbutadienes of the formula I, where the diene system has the Z,Z; Z,E; E,Z or E,E configuration or a mixture thereof, and where the variables independently of one another have the following meanings: R1 and R2 are hydrogen, C1-C20-alkyl, C2-C10-alkenyl, C3-C10-cycloalkyl, C3-C10-cycloalkenyl, C1-C12-alkoxy, C1-C20-alkoxycarbonyl, C1-C12-alkylamino, C1-C12-dialkylamino, aryl, hetaryl, unsubstituted or substituted, substituents which confer solubility in water and are selected from the group consisting of carboxylate, sulfonate, or ammonium residues; R3 is COOR5, CONR5R6; R4 is COOR6, CONR5R6; R5 and R6 are hydrogen, C1-C20-alkyl, C2-C10-alkenyl, C3-C10-cycloalkyl, C7-C10-bicycloalkyl, C3-C10-cycloalkenyl, C7-C10-bicycloalkenyl, aryl, hetaryl, unsubstituted or substituted; n is 1 to 3; and R3 and R4 are not COOCH3 when R1 and R2 are hydrogen, are used as photostable UV filters in cosmetic and pharmaceutical preparations to protect the human skin or human hair from the sun's rays,

Abstract: 4,4-Diarylbutadienes of the formula I, where the variables have the meanings explained in the description, are used as photostable UV filters in cosmetic and pharmaceutical preparations to protect the human skin or human hair from the sun's rays, alone or together with compounds which absorb in the UV region and are known per se for cosmetic and pharmaceutical preparations.