Acetone → 6-fluoro-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

In a 500 mL round-bottomed flask was added 1-(5-fluoro-2-hydroxyphenyl)ethanone (20.0 g, 130 mmol, Aldrich Chemical), propan-2-one (19.0 mL, 260 mmol), and pyrrolidine (21.5 mL, 260 mmol) in methanol (150 mL) to give a orange solution. The reaction mixture was stirred at ambient temperature for 48 h. The reaction mixture was poured into EtOAc (200 mL) and washed with 1N HCl (50 mL), saturated NaHCO3 (50 mL), and brine (50 mL). The organic portion was dried (Na2SO4), filtered, and concentrated to provide an orange residue which was purified by silica gel chromatography (gradient elution, 0-20% EtOAc/hexanes) to provide the title compound (14.2 g, 73.1 mmol, 56%) as a white solid. MS (DCI/NH3) m/z 208 (M+NH4)+.

1. customto give a orange solution
2. washwashed with 1N HCl (50 mL), saturated NaHCO3 (50 mL), and brine (50 mL)
3. dry with materialThe organic portion was dried (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customto provide an orange residue which
7. customwas purified by silica gel chromatography (gradient elution, 0-20% EtOAc/hexanes)

ORD record

ord-4127aacb217d4767b2c0ad35fd8bc043

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08609692B2