Pyrrolidine → 6,8-Difluoro-2,2-bis(fluoromethyl)chroman-4-one

Participants

Reaction Steps

A solution of 1-(3,5-difluoro-2-hydroxyphenyl)ethanone (4.98 g, 28.9 mmol), MeOH (50 mL), 1,3-difluoroacetone (5.44 g, 57.9 mmol), and pyrrolidine (4.79 mL, 57.9 mmol) was heated at 60° C. for 20 hours. The dark solution was cooled, concentrated, chased with toluene, and then passed through a silica gel plug, washing with toluene (200 mL) and MTBE (200 mL). The filtrate was washed with 2N NaOH (50 mL×2), dried (Na2SO4), filtered, and concentrated to afford the title compound (5.80 g, 23.37 mmol, 81%), which was used without further purification in the next step. MS (DCI) m/z 299 (M+51)+.

Provenance & Evidence