Dimethylformamide → Di-tert-butyl [4-[[4-chloro-2-(4-fluoro-2-methyl-phenoxy)benzoyl]amino]-2-oxo-1-pyridyl]methyl phosphate

Participants

Reaction Steps

A solution of 4-chloro-2-(4-fluoro-2-methyl-phenoxy)-N-(2-oxo-1H-pyridin-4-yl)benzamide (13a) (99 mg, 0.2656 mmol) and chloromethyl chloroformate (82.19 mg, 55.35 μL, 0.6374 mmol) in THF (2 mL) was added DMF (0.2 mL) and CH2Cl2 (0.5 mL) and was stirred at room temperature for 2 hours. The reaction mixture was diluted with EtOAc and the organic phase washed with sat. aq. NaHCO3, brine, dried with Na2SO4 and evaporated to dryness. The residue was taken up in DMF (1 mL), di-tert-butoxyphosphoryloxypotassium (263.7 mg, 1.062 mmol) and tetrabutylammonium iodide (9.810 mg, 0.02656 mmol) were added and the reaction mixture was stirred at 70° C. for 4 hours. The reaction mixture was cooled, diluted with water and extracted with EtOAc (3×). The organic phases were combined, washed with water then brine, dried with Na2SO4 and evaporated to dryness. Purification by column chromatography (12 g silica; 0-100% EtOAc in Hx) gave di-tert-butyl [4-[[4-chloro-2-(4-fluoro-2-methyl-phenoxy)benzoyl]amino]-2-oxo-1-pyridyl]methyl phosphate (23) (35 mg, 0.05882 mmol, 22.2%) as a clear foam. ESI-MS m/z calc. 594.1698, found 595.5 (M+1)+; Retention time: 0.77 minutes.

Provenance & Evidence