Triethylamine → Diethyl 2-(3-(3-(2,6-dichlorophenyl)isoxazol-5-yl)phenylamino)ethylphosphonate

Participants

Reaction Steps

2,6-Dichloro-N-hydroxybenzimidoyl chloride (370 mg, 1.6 mmol) and diethyl 2-(3-ethynylphenylamino)ethylphosphonate (450 mg, 1.6 mmol) were dissolved in anhydrous tetrahydrofuran (40 mL) and triethylamine (0.30 mL, 1.6 mmol). The mixture was then heated at reflux for 5 h. The reaction was cooled to room temperature and the solvent was removed under reduced pressure. The residue was dissolved in ethyl acetate and washed successively with water and brine. The ethyl acetate solution was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The resulting solid was purified by flash column chromatography on silica gel, eluting with 98:2 methylene chloride:methanol to give diethyl 2-(3-(3-(2,6-dichlorophenyl)isoxazol-5-yl)phenylamino)ethylphosphonate (670 mg) as a pale yellow oil. 1H NMR (CDCl3): 7.30 (m, 2H), 7.21 (m, 1H), 7.15 (m, 1H), 7.05 (m, 1H), 7.00 (m, 1H), 6.59 (m, 1H), 6.48 (s, 1H), 4.03 (m, 4H), 3.40 (m, 2H), 2.00 (m, 2H), 1.24 ppm (m, 6H). MW=469 confirmed by LC-MS, tr=14.80 min (Method Y) MH+=467-472.

Provenance & Evidence