N-Fluorobenzenesulfonimide → 3-Fluoro-6-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid

Participants

Reaction Steps

A solution of 6-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid 10a (2.031 mmol, 0.50 g) in THF (8 mL) at −70° C. was treated with a 1.6 M solution of n-BuLi in hexanes (4.26 mmol, 2.66 mL). After 1 h at −70° C., N-fluorobenzenesulfonimide (2.64 mmol, 0.833 g) in THF (2 mL) was slowly added and the reaction was warmed to room temperature. After 1 h the mixture was partitioned between dilute aqueous HCl and EtOAc. The organic layer was washed with water and brine, and then concentrated. The residue was triturated with CH2Cl2. The off-white precipitate was filtered and collected to provide 61a.

Provenance & Evidence