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: This invention relates to herbicidal compositions containing N-(phosphonomethyl)-glycine or a non-phytotoxic salt thereof, in combination with 2,4-dichlorophenoxyacetic acid or .alpha.-naphthylacetic acid or non-phytotoxic salt of these compounds.By using the compositions according to the invention the herbicidally effective amount of N-(phosphonomethyl)-glycine can considerably be reduced in comparison with the commercially available compositions, which contain N-(phosphonomethyl)-glycine as an only active ingredient.