A solution of 0.6 mL (8 mmol) of dimethyl sulfide in 65 mL of dichloromethane was cooled to -20° C. and then 0.4 g (6 mmol) of chlorine was slowly sparged in with stirring and cooling to maintain the temperature below -15° C. A mixture of 5.0 g (31 mmol) of 2,6-dichloroaniline and 6.3 g (49 mmol) of quinoline was then added with cooling and stirring to form a mixture of the sulfilimine catalyst, unreacted 2,6-dichloroaniline, and quinoline. The mixture was allowed to warm to 0° C. and 10 g (45 mmol) of 2-chlorosulfonyl-7,8-dichloro[1,2,4]triazolo[1,5-c]pyrimidine was added with stirring and cooling. The mixture was allowed to warm to about 20° C. and stir for about 16 hours. It was then diluted with 50 mL of methanol and the solids that formed were collected by filtration, washed 2×30 mL with methanol, and dried to obtain 6.2 g (80 percent of theory) of the title compound as a white solid having uv maxima at 210 and 270 nm.
