Propylene Glycol → Florasulam

Participants

Reaction Conditions

Reaction Steps

A jacketed 250 mL (milliliter) round bottom flask equipped with a stirrer, condenser, and nitrogen inlet and outlet was loaded with 49.1 g (grams), 0.38 mol (mole) of 2,6-difluoroaniline and 25 g of 1,2-propanediol. The mixture was warmed to 35° C. by heating the jacket fluid and a solution of 30.3 g of 93 percent purity (0.10 mol) of 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine in 30.2 g of dichloromethane was added portionwise with stirring under a nitrogen blanket over 3.5 hours. A solid began to form in about one hour and all of the chlorosulfonyl starting material was consumed in 5.5 hours. The resulting mixture was cooled to 20° C. and filtered, collecting the solids. The solids were washed 2×40 mL with methanol and then with 112 g of water. The white solid obtained after drying was found to be the title compound with a purity of greater than 99 percent and to amount to 34.2 g (88.9 percent of theory).

Provenance & Evidence