Ethyl ketone → 2,2-Diethyl-6-fluorochroman-4-one

Participants

Reaction Conditions

Reaction Steps

1-(5-Fluoro-2-hydroxyphenyl)ethanone (30.2 g, 196 mmol) and MeOH (300 mL) were stirred at ambient temperature and 3-pentanone (41.6 mL, 392 mmol) and pyrrolidine (17.8 mL, 216 mmol) were added. The mixture was heated to 60° C. for 62 h at which point LCMS analysis showed clean conversion to product. The reaction was cooled, concentrated to a minimal volume of MeOH, and MTBE (300 mL) was added. The organics were washed with 2N HCl (150 mL), brine (60 mL), 2N NaOH (150 mL), and brine (60 mL). The solution was passed through a plug of silica gel (30 g), washing with MTBE (150 mL). The filtrate was concentrated, giving the title compound (38.8 g, 175 mmol, 89%) as a light brown oil. MS (DCI/NH3) m/z 240 (M+NH4)+.

Provenance & Evidence