Triethylamine → 2-Fluoro-1-(2-fluoro-phenyl)-ethanone

Participants

Reaction Steps

A solution of 1-(2-fluorophenyl)-2-hydroxyethanone [CAS 218771-68-7; WO9857925, ex. 16) (2.77 g, 18.0 mmol) in dichloromethane (42 ml) was treated consecutively at 0° C. with triethylamine (6.36 g, 62.8 mmol), triethylamine trihydrofluoride (3.05 g, 18.0 mmol) and nonafluoro-n-butanesulfonylfluoride (8.48 g, 26.9 mmol). The tube was sealed and the reaction mixture stirred overnight at room temperature. For the workup, the dark red solution was poured on a saturated solution of sodium hydrogencarbonate and ice, then extracted with dichloromethane. The organic layer was separated, dried over sodium sulphate and evaporated. The crude material was purified by flash chromatography on silica gel (Telos Flash Silica) using dichloromethane as the eluent to give the 2-fluoro-1-(2-fluoro-phenyl)-ethanone (1.23 g, 61% of theory) as a yellow semisolid.

Provenance & Evidence