N-[1-(chloromethyl)-2-oxo-4-pyridyl]-2-(4-fluoro-2-methyl-phenoxy)-4-(trifluoromethyl)benzamide → Di-tert-butyl [4-[[2-(4-fluoro-2-methyl-phenoxy)-4-(trifluoromethyl)benzoyl]amino]-2-oxo-1-pyridyl]methyl phosphate

Participants

Reaction Conditions

Reaction Steps

The crude N-[1-(chloromethyl)-2-oxo-4-pyridyl]-2-(4-fluoro-2-methyl-phenoxy)-4-(trifluoromethyl)benzamide from the previous step was taken up in N,N-dimethylformamide (5 mL). Di-tert-butoxyphosphoryloxypotassium (496.6 mg, 2.0 mmol) and tetrabutylammonium iodide (36.94 mg, 0.10 mmol) were added and the reaction mixture was stirred at 70° C. for 4 hours. The reaction mixture was then diluted with ethyl acetate and washed with water then brine, dried with Na2SO4, filtered and evaporated to dryness. The material was purified by column chromatography (40 g silica, 50-100% EtOAc in Hexanes), fractions with the product were pooled and evaporated to give di-tert-butyl [4-[[2-(4-fluoro-2-methyl-phenoxy)-4-(trifluoromethyl)benzoyl]amino]-2-oxo-1-pyridyl]methyl phosphate (20) (280 mg, 45%) as a yellow oil that was used in the next step without further purification. ESI-MS m/z calc. 628.20, found 629 (M+1)+; Retention time: 0.76 minutes (1 minute run).

Provenance & Evidence