Ethyl Acetate → N-[1-(chloromethyl)-2-oxo-4-pyridyl]-2-(4-fluoro-2-methyl-phenoxy)-4-(trifluoromethyl)benzamide

Participants

Reaction Steps

To a 50 liter jacketed glass reactor fitted with an N2 inlet and a mechanical stirrer, and with a jacket temperature set at 20° C., was added 2-(4-fluoro-2-methylphenoxy)-N-(2-oxo-1,2-dihydropyridin-4-yl)-4-(trifluoromethyl)benzamide (9a, 2482.0 g, 6.11 moles, 1.0 eq) under nitrogen. Ethyl acetate (25 liters) was added with stirring at 100 rpm followed by 1,4-diazabicyclo [2.2.2] octane (DABCO) (342.6 g, 3.05 moles, 0.5 eq) and DMF (1.25 liters, Sigma-Aldrich). Chloromethyl chloroformate (815 ml, 9.16 moles, 1.5 eq) was then added over 30 minutes. When the addition of chloromethyl chloroformate was complete, the jacket temperature was ramped up to 60° C. over 30 minutes. The resulting yellow-slurry was stirred for 3 hours at about 60° C., at which time the reaction was judged to be complete by HPLC analysis. The jacket temperature was ramped down to 15° C. over 20 minutes before quenching the reaction by slow addition of water (500 ml) over 10 minutes. Additional water was added, and the mixture stirred at 115 rpm for 15 minutes. Stirring was stopped, the aqueous layer was discarded, and the organic layer washed with water (5 liters), followed by a saturated solution of NaHCO3 (137 g) in water (620 ml). The organic layer was seeded with 5 g of N-(1-(chloromethyl)-2-oxo-1,2-dihydropyridin-4-yl)-2-(4-fluoro-2-methylphenoxy)-4-(trifluoromethyl)benzamide (7), and the resulting slurry was partially concentrated (removed 18.5 liters of organics) in the rotovap (40° C., vacuum). The resulting suspension was stored at room temperature under nitrogen atmosphere overnight, during which time additional material crystallized out of solution. The remaining solvent was chased with heptanes adding more heptanes as needed to maintain the volume at 10 liters. The thick suspension was stirred on the rotovap at room temperature for 45 minutes, and then the solids were collected by filtration. The off-white solid was washed with heptanes (2.5 liters), then dried in vacuo (40° C., full house vacuum) to give 2409 g (87%) of N-(1-(chloromethyl)-2-oxo-1,2-dihydropyridin-4-yl)-2-(4-fluoro-2-methylphenoxy)-4-(trifluoromethyl)benzamide as an off-white crystalline solid.

Provenance & Evidence