B. Add 5.1 g (40 mmol) of 2,6-difluoroaniline, 10 mL of alcohol solvent, and a small amount of naphthalene crystals (as an internal standard for liquid chromatography) to a 50 mL flask, and heat the mixture to 40 °C. Under nitrogen protection and stirring conditions, 2.67 g (10 mmol) of 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine solid was slowly added until the chlorosulfonyl feedstock completely disappeared (monitored by high-pressure liquid chromatography). After completion of the reaction, the mixture was cooled to room temperature and the solid product was collected by filtration. The solid was washed with 10 mL of 2-propanol followed by water and dried. The resulting N-(2,6-difluorophenyl)-8-fluoro-5-methoxy-[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamide was more than 99% pure (results are shown as Runs 4 through 6 in the table below).
![[1,2,4]Triazolo[1,5-c]pyrimidine-2-sulfonyl chloride, 8-fluoro-5-methoxy-](/CAS/20200611/GIF/147150-78-5.gif)
