Abstract: Chlorosulfonyl substituted aromatic heterocyclic compounds, such as 2-chlorosulfonyl[1,2,4]triazolo[1,5-c]pyrimidine compounds, were prepared in good yield by chloroxidation of di(aromatic heterocyclyl) disulfide compounds in a medium containing water, a water-immiscible organic solvent, and a phase transfer catalyst, such at tetrabutylammonium chloride.

Abstract: N-arylsulfilimine compounds, such as S,S-dimethyl-N-(2,6-dichlorophenyl)sulfilimine, were prepared and found to catalyze the reaction of aromatic sulfonyl chloride compounds, such as 2-chlorosulfonyl-7-fluoro-5-ethoxy[1,2,4]triazolo[1,5-c]pyrimidine, with aromatic amine compounds, such as 2,6-dichloroaniline, to form N-arylarylsulfonamide compounds, such as N-(2,6-dichlorophenyl)-7-fluoro-5-ethoxy[1,2,4]triazolo[1,5-c]pyrimidine-2 -sulfonamide. The aryl moiety of the N-arylsulfilimine catalyst and the aryl moiety of the aromatic amine compound were generally chosen to be identical.

Abstract: N-arylsulfilimine compounds, such as S,S-dimethyl-N-(2,6-dichlorophenyl)sulfilimine, were prepared and found to catalyze the reaction of aromatic sulfonyl chloride compounds, such as 2-chlorosulfonyl-7-fluoro-5-ethoxy[1,2,4]triazolo[1,5-c]pyrimidine, with aromatic amine compounds, such as 2,6-dichloroaniline, to form N-arylarylsulfonamide compounds, such as N-(2,6-dichlorophenyl)-7-fluoro-5-ethoxy[1,2,4]triazolo[1,5-c]-pyrimidine- 2-sulfonamide. The aryl moiety of the N-arylsulfilimine catalyst and the aryl moiety of the aromatic amine compound were generally chosen to be identical.

Abstract: N-(substituted aryl)?1,2,4!triazoloazinesulfonamide compounds, such as N-(2,6-difluorophenyl)-8-fluoro-5-methoxy?1,2,4!triazolo?1,5-c!pyrimidine- 2-sulfonamide, were prepared at a good reaction rate and in good yield by the reaction of a chlorosulfonyl?1,2,4!triazoloazine compound, such as 2-chlorosulfonyl-8-fluoro-5-methoxy?1,2,4!triazolo?1,5-c!pyrimidine, and an arylamine compound, such as 2,6-difluoroaniline, in an organic medium containing a relatively acidic alcohol, such as propylene glycol or 2,2,2-trifluoroethanol.

Abstract: A salt of 2-ethoxy-4,6-dihydroxypyrimidine (DHEP) is prepared by contacting a salt of O-ethylisourea with dimethyl malonate in the presence of a methoxide base to form the salt of DHEP. The salt of DHEP can optionally be protonated with an acid to form neutral DHEP. The reaction is typically conducted in a methanol solvent at a temperature less than about 30.degree. C. Typically, the monosodium salt of DHEP is prepared by contacting O-ethylisourea hydrochloride with dimethyl malonate in the presence of sodium methoxide and methanol solvent.

Abstract: 2-Chlorosulfonyl-5-alkoxy[1,2,4]triazolo-[1,5-c]pyrimidine compounds, such as 2-chlorosulfonyl-5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine, that are useful for the preparation of 5-alkoxy[1,2,4]triazolo [1,5-c]pyrimidine-2-sulfonamide herbicides, were prepared in an improved manner from 5-alkoxy[1,2,4]triazolo [1,5-c]pyrimidine-2(3H)-thione compounds, such as 5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine-2(3H)-thione, by oxidation with hydrogen peroxide to obtain novel 2,2'-dithiobis(5-alkoxy[1,2,4]triazolo[1,5-c]pyrimidine) compounds, such as 2,2'-dithiobis (5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine), and subsequent chloroxidation of these intermediate compounds.