2,6-Difluoroaniline → Flumetsulam

Participants

Reaction Steps

The starting 2,6-difluoroaniline (18.1 g, 0.140 mol) was dissolved in 45 ml of pyridine and 36.1 g (0.155 mol) of 5-methyl-1,2,4-triazolo[1,5-a]pyrimidine-2-sulfonyl chloride was added. After an exothermic reaction subsided the reaction mixture was stirred at room temperature for 15.5 hours. The pyridine was removed by evaporation at reduced pressure, and the residue was treated with 600 ml of 0.5N NaOH. After stirring to dissolve all soluble material the mixture was filtered through celite and the filtrate was acidified with 3N HCl. The precipitate which separated upon acidification was collected by filtration and dried to yield 33.0 g (73%) of the desired product as a pale red solid, m.p. 245°-247° C. IR and 1H NMR spectra were in agreement with the assigned structure.

Provenance & Evidence