N,N-Dimethylhexanamide → N-(2-fluoro-4-hexanoyl-6-methylphenyl)-2,2-dimethylpropanamide

Participants

Reaction Conditions

Reaction Steps

A solution of N-(4-bromo-2-fluoro-6-methylphenyl)-2,2-dimethylpropanamide (21.7 g, 79.2 mmol) in anhydrous tetrahydrofuran (500 mL) was placed under a nitrogen atmosphere, cooled in a dry ice-acetone bath, and stirred while butyllithium (124 mL of a 1.6M solution in hexanes, 198 mmol) was added dropwise. The resulting mixture was aged at −78° C. for 30 minutes and then treated with N,N-dirnethylhexanamide (28.3 g, 198 mmol). After warming up to 0° C. over 2 hours, the mixture was removed from the cooling bath and treated with aqueous saturated NH4Cl (20 mL). The resulting slurry was diluted with CH2Cl2 (1000 mL), dried over MgSO4, filtered through a pad of silica, and concentrated under vacuum. The residue was purified by flash chromatography on a Biotage 40M KP-Sil column, eluting with 19:1 to 9:1 hexanes-EtOAc. The product containing fractions were evaporated under vacuum to provide N-(2-fluoro-4-hexanoyl-6-methylphenyl)-2,2-dimethylpropanamide (12.7 g, 55%) as a yellow foam.

Provenance & Evidence