Triethylamine → Methyl 5-formyl-2-(trifluoromethylsulfonyloxy)benzoate

Participants

Reaction Steps

To a solution of 5-formyl-2-hydroxy-benzoic acid methyl ester (1.0 g, 5.6 mmol) in CH2Cl2 (10 mL) at −78° C. was added Et3N (0.85 mL, 6.1 mmol) and DMAP (68 mg, 0.56 mmol) followed by dropwise addition of Tf2O (1.03 mL, 6.1 mmol) over 20 min. The reaction mixture was then warmed to room temperature and poured into saturated aqueous NH4Cl and extracted with CH2Cl2 (3×25 mL). The combined extracts were dried (Na2SO4), filtered and concentrated. The residue was purified by flash chromatography (SiO2, 15% EtOAc/hexanes) to afford Example 236A (1.3 g, 76%) as a colorless oil.

Provenance & Evidence