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.

Abstract: 2,3-Difluoro-5-(trifluoromethyl)pyridine is prepared by contacting a 2,3-dihalo-5-(trifluoromethyl) pyridine with an effective amount of KF or CsF in a polar aprotic solvent (diluent) at an elevated temperature under substantially anhydrous conditions with removal of the difluoropyridine products essentially as they are formed. The starting material may optionally be added as the reaction proceeds to minimize decomposition. The reaction is also optionally conducted in the presence of an acid scavenger and/or a crown ether or other phase-transfer catalyst.