Formic Acid → [3-[4-Chloro-2-(2-fluorobenzoyl)-phenyl]-3-oxopropyl]-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of {3-[4-chloro-2-(2-fluoro-benzoyl)-phenyl]-prop-2-ynyl}-carbamic acid tert-butyl ester (9.2 g, 23 mmol) in CH2Cl2 (100 mL) containing formic acid (9.18 mL) was cooled to 0° C. Mercury(II) sulphate (2.1 g, 7.1 mmol) was added and the reaction stirred for 2 h at 0° C. The mixture was diluted with H2O (20 mL) and NH4OH (20 mL). The organic phase was collected and the aqueous phase was extracted with EtOAc (3×100 mL). The combined organic portions were washed with H2O, dried over MgSO4, filtered and the solvents evaporated in vacuo to afford [3-[4-chloro-2-(2-fluorobenzoyl)-phenyl]-3-oxopropyl]-carbamic acid tert-butyl ester 8.9 g (95%) as a brown solid. This material (8.9 g, 22 mmol) was dissolved in HCl (4N in dioxane, 185 mL) and stirred at room temperature for 30 min. The solution was then evaporated in vacuo. The residue was dissolved in CH2Cl2 (250 mL) and diisopropylethylamine amine (18 mL) was added. The solution was stirred at room temperature for 2 h. The solution was evaporated in vacuo and the residue purified by column chromatography (silica gel, 10 to 50% EtOAc/hexanes) to provide 4k (2.9 g, 46%) as a brown solid MS m/z=288 (M+H).

Provenance & Evidence