Hydrochloric Acid → 7-bromo-3-chloro-1-fluoro-5-methylene-5H-chromeno[2,3-c]pyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of 7-bromo-3-chloro-1-fluoro-5-methyl-5H-chromeno[2,3-c]pyridin-5-ol (50 g, 145 mmol) in THF (300 mL) was added HCl in dioxane (4M, 19.95 mL, 80 mmol). The reaction was heated to 50° C. for 16 hours. The reaction was cooled to RT and K2CO3 (30.1 g, 218 mmol) was added. The reaction mixture was stirred for 30 minutes before filtering. The filtrate was concentrated under reduced pressure and the resulting crude material was washed with DCM. The solid was collected by filtration to afford 7-bromo-3-chloro-1-fluoro-5-methylene-5H-chromeno[2,3-c]pyridine (33.0 g, 101 mmol, 69.6% yield).

Provenance & Evidence