1.8 g (6 mmol) N-(2-Difluoromethoxy-6-methylphenyl)-1H-1,2,4-triazole-3-sulphonamide in 10 ml dimethylformamide was stirred with 1.68 g (12 mmol) potassium carbonate for 10 minutes at 50° C. It was then cooled to 10° C. and treated with 1.33 g (6 mmol) 4-chloro-6-methoxy-2-methylsulphonylpyrimidine and the mixture stirred for 45 minutes at 10° C. It was then added to ice-water, acidified to pH 4 with sulphuric acid and the solid collected and purified by silica gel chromatography using a mixture of methylene chloride and methanol (95/5).
