Trifluoroacetic acid → Methyl 3-((di-tert-butoxyphosphoryloxy)methyl)benzoate

Participants

Reaction Steps

To a stirred mixture of methyl 3-(bromomethyl)benzoate (1.08 g, 4.71 mmol) in DMF (20 mL) was added tetrabutylammonium di-tert-butyl phosphate (2.34 g, 5.19 mmol). The mixture was stirred at room temperature for 1.5 h, then diluted with ether and washed sequentially with 10% LiCl solution and brine. The organic layers were dried over anhydrous magnesium sulfate, filtered and concentrated. The crude material was purified by flash chromatography (Teledyne ISCO CombiFlash 0% to 100% solvent A/B=hexane/EtOAc, REDISEP® SiO2 40 g, detecting at 254 nM, and monitoring at 220 nM). Concentration of appropriate fractions provided Preparation 46A (1.38 g, 82%): HPLC: RT=3.163 min (H2O/MeOH with TFA, CHROMOLITH® ODS, 4.6×50 mm, gradient=4 min, wavelength=220 nm); MS(ES): m/z=359 [M+H+]; 1H NMR (400 MHz, DMSO-d6) δ 8.01 (s, 1H), 7.94-7.89 (m, 1H), 7.66 (d, J=7.9 Hz, 1H), 7.58-7.48 (m, 1H), 5.01 (d, J=8.4 Hz, 2H), 3.86 (s, 3H), 1.41 (s, 18H).

Provenance & Evidence