Ethyl fluoroacetate → HCID 86732164, compound

Participants

Reaction Conditions

Reaction Steps

To a 3-neck 500-mL round bottomed flask was added THF (180 mL). The solvent was cooled to −78° C. and lithium diisopropylamide, (Aldrich; 40.3 mL, 81 mmol, 2.0 M solution in tetrahydrofuran/heptane/ethylbenzene) was added over 2 min. To the solution was added 2-bromo-5-fluoro-4-(triethylsilyl)pyridine (11a, synthesized according to procedure in WO 2012/095469 A1; 18.0 g, 62.0 mmol) in 5 mL THF over 5 min. The temperature was not allowed to go above −70° C. during the addition. After 50 min, ethyl fluoroacetate (Aldrich; 7.79 mL, 81 mmol) was added over 3 min. The temperature was not allowed to go above −60° C. during the addition. The solution was stirred at −78° C. for 10 min and then the cold bath was removed and the solution was allowed to warm to −40° C. At that point the solution was poured into a solution of 1 N HCl/10% NH4Cl (1:1, 200 mL). The solution was extracted with EtOAc (3×200 mL) and the combined extracts were washed with brine (100 mL), dried (Na2SO4) and concentrated onto silica. Purification by silica gel chromatography (Gradient: 0.0 to 20% EtOAc/hexane) afforded 1-(6-bromo-3-fluoro-4-(triethylsilyl)pyridin-2-yl)-2-fluoroethanone (20.35 g, 58.1 mmol, 94% yield) as a yellow oil. MS m/z=350.0 [M+H]+. Calculated for C13H18BrF2NOSi: 349.0.

Provenance & Evidence