Trifluoroacetic anhydride → 1-(4-methoxybenzyl)-3,4-dihydropyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

1-(4-methoxybenzyl)piperidine-2,6-dione (8.99 g, 38.5 mmol) was dissolved in Toluene (Volume: 128 ml) and cooled to −78° C. L-Selectride (42.4 ml, 42.4 mmol) was added dropwise and the mixture agitated for 1 h. After 1 h, thick slurry along with precipitate observed. Reaction mixture was briefly pulled outside cooling bath to homogenize the mixture. Then DMAP (0.047 g, 0.385 mmol) was added in one portion and then DIEA (38.4 ml, 220 mmol) was added and then TFAA (6.53 ml, 46.2 mmol) was added. Then the cooling flask was removed and the mixture agitated at room temperature for 2 h and then quenched with water and the product extracted with EtOAc. The combined organic layer was dried (MgSO4), filtered and concentrated in vacuo to afford crude residue which was purified by flash chromatography to afford 7.66 g of the desired product as a yellow syrup. LCMS (m/z): (MH+), 234.2, 0.73 min.

Provenance & Evidence