5-alkoxy-1,2,4-triazoloÝ4,3-c¨pyrimidine-3(2h)-thione compounds and their use in the preparation of 5-alkoxyÝ1,2,4¨triazoloÝ1,5-c¨pyrimidine-2(3h)-thione and 3-hydrocarbylthio-5-alkoxy-1,2,4-triazoloÝ4,3-c¨pyrimidine compounds

• Main Authors: JON A. ORVIK, DAWN L SHIANG
• Format: Patent
• Language: English
• Published: 23.05.1995
• Edition: 6
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

5-Alkoxy[1,2,4]triazolo[1,5-c]pyrimidine-2 (3H)-thione compounds, such as 5-ethoxy-8-fluoro[1,2,4]triazolo[1,5-c]pyrimidine-2(3H)-thione, were prepared by treatment of a 5-alkoxy-1,2,4-triazolo-[4,3-c]pyrimidine-3(2H)-thione compound, such as 5-ethoxy-8-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione, with an alkali metal alkoxide in an alcohol solvent selected so that the 5-alkoxy group, the alkoxide, and the alcohol all have the same alkyl group. The trialkylammonium salts of the 5-alkoxy-1,2,4-triazolo [4,3-c]pyrimidine-3(2H)-thione compounds were converted to 3-hydrocarbylthio-5-alkoxy-1,2,4-triazolo-[4,3-c]pyrimidine compounds by reaction with a hydrocarbyl halide, such as benzyl chloride. The products are useful intermediates in the preparation of 5-alkoxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamide herbicides.