Vinylidene chloride → 3,3-Dichloro-1-(2,6-dichloro-5-fluoro-3-pyridinyl)-2-propen-1-one

Participants

Reaction Conditions

Reaction Steps

A solution of the 2,6-dichloro-5-fluoronicotinoyl chloride from the previous reaction in CH2Cl2 (25 mL) was added slowly to a cooled (0° C.) and stirred slurry solution of AlCl3 (7.9 g, 59.5 mmol) in CH2Cl2 (25 mL). After 15 min, vinylidene chloride (4.75 mL, 59.5 mmol) was added to the mixture dropwise. The reaction was allowed to warm to room temperature and was stirred overnight. The mixture was poured over ice and partitioned with CH2Cl2. The organic layer was collected and cooled to 0° C. before TEA (8.3 mL, 59.5 mmol) was added. After 15 min, the ice bath was removed and the reaction was allowed to warm to room temperature and stirred for an additional 30 min. The solution was washed with 1N HCl, NaHCO3, and water. The organic layer was passed through a pad of silica gel and concentrated in vacuo to afford 3,3-dichloro-1-(2,6-dichloro-5-fluoro-3-pyridinyl)-2-propen-1-one: (6.1 g, 90%) as a brown oil: 1H-NMR (d6-DMSO, 300 MHz) δ 8.43 (d, 1H, J=8.4 Hz), 7.56 (s, 1H), Rf=0.76 (3:1 Hex:EtOAc).

Provenance & Evidence