Abstract: The invention relates to an improvement of a process for preparing N-phosphonomethyl-glycine by oxydation of N-phosphonomethyl-imino-diacetic acid in an aqueous sulphuric acidic medium with hydrogen peroxide.A characteristic feature is using a waste acid liquor as reaction medium formed as aqueous sulphuric acid and obtained after the separation of N-phosphonomethyl-glycine when carrying out oxydation. This solution is optionally diluted with water until a concentration of 12-18 weight % of sulphuric acid and 3-5 weight % of N-phosphonomethyl-glycine.

Abstract: The invention relates to the preparation of N-phosphono-methyl-imino-diacetic acid from the calcium salt of imino-diacetic acid in a simplified synthesis. The process comprises in that the imino-diacetic acid calcium salt is heated with concentrated hydrochloric acid in a molar ratio of 2-3:1 at a temperature between 50.degree.-100.degree. C., the obtained imino-diacetic acid hydrogen-chloride is separated then dissolved in water and is reacted with phosphorous acid in a molar ratio of 1.0-1.2:1 calculated for imino-diacetic acid hydrogen chloride and with the aqueous solution of formaldehyde in a molar ratio of 1.0-1.4:1 under stirring, and the obtained product is isolated.

Abstract: The present invention relates to a process for the preparation of 3-isopropyl-benzo-2-thia-1,3-diazinone-(4)-2,2-dioxide which comprises preparing isopropyl sulfamoyl chloride in one step by reacting N,N'-diisopropyl-urea with phosphorus trichloride and chlorine in the presence of oleum and sulfuric acid and condensing the so obtained isopropyl sulfamoyl chloride at room temperature without any solvent in the presence of an excess of N,N-diethyl aniline with anthranylic acid methyl ester and subjecting the thus obtained N-isopropyl-N'-o-carbomethoxy-phenyl-sulfamide to cyclization in the presence of sodium methylate, extracting the obtained crude 3-isopropyl-benzo-2-thia-1,3-diazinone-(4)-2,2-dioxide with a mixture of methanol and water and after adding water to the aqueous-methanolic mixture and sedimenting the contaminations isolating a product of high purity.

Abstract: The invention relates to an improved method for the preparation of a 2',6'-dialkyl-N-alkoxymethyl-2-chloro-acetanilide compound of the general formula (I), ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are identical or different and stand for straight-chained or branched C.sub.1-4 alkyl groups.According to the invention a dialkyl aniline of the general formula (II), ##STR2## wherein R.sub.1 and R.sub.2 are as defined above, is treated with aqueous formaldehyde solution in an apolar solvent at a temperature of 30.degree. to 80.degree. C., the solution of the resulting oxymethyl derivative formed with said apolar solvent is separated from the aqueous formaldehyde solution at an elevated temperature and then dehydrated, the resulting azomethine derivative is reacted with chloroacetyl chloride in the same apolar solvent medium, the resulting chloromethyl compound is reacted with an alcohol of the general formula (V),R.sub.3 -OH (V)wherein R.sub.