3,5-Dimethylpyridine → Penoxsulam

Participants

Reaction Steps

2-Amino-5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidine (7.8 g, 0.040 mol) and 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzenesulfonyl chloride (13 g, 0.040 mol) were combined in 3,5-lutidine (31 g, 0.29 mol, 7.2 eq). The slurry was treated with methyl sulfoxide (0.040 g, 0.0005 mol, 0.012 eq) and stirred at ambient conditions for 8.5 hours. The reaction slurry was filtered, and the wet cake solids were slurried in a mixture of 15% sulfuric acid (80 mL) and acetonitrile (20 mL). The mixture was stirred for 25 minutes, then filtered, and the solids washed with water. After drying under vacuum at 55° C., 18 g of product was obtained as a white solid assaying at 97.4 wt % (91% yield).

Provenance & Evidence