Pyridine → Ethyl 3-oxo-4-phenylpentanoate

To a solution of 2-phenylpropanoic acid (5.0 g, 33.3 mmol) in DCM (50 mL) was added (COCl)2 (8.5 g, 66.7 mmol) and 2 drops of DMF in ice-bath. The reaction mixture was stirred at r.t. for 2 h. After the reaction was completed, the reaction mixture was concentrated under reduced pressure. To a solution of pyridine (6 mL) in DCM (50 mL) was added 2,2-dimethyl-1,3-dioxane-4,6-dione (5.8 g, 40.0 mmol) and the above residue in ice-bath. The reaction mixture was stirred at r.t. for 2 h. Diluted with 1N HCl (50 mL), extracted with DCM (50 mL×3), washed with brine (50 mL), dried over Na2SO4, filtered, concentrated to give a residue. The residue was dissolved in EtOH (50 mL) and then stirred at reflux for 3 h. Removed solvent, purified by flash column chromatography to give the title compound (3.6 g, 49%) as a yellow oil. 1H NMR (400 MHz, CDCl3): δ 1.22 (3H, t, J=7.2 Hz), 1.41 (3H, d, J=7.2 Hz), 3.28 (1H, d, J=15.6 Hz), 3.40 (1H, d, J=15.6 Hz), 3.89-3.91 (1H, m), 4.11-4.14 (2H, m), 7.20-7.22 (2H, m), 7.27-7.36 (3H, m).

1. concentrationthe reaction mixture was concentrated under reduced pressure
2. stirringThe reaction mixture was stirred at r.t. for 2 h
3. extractionextracted with DCM (50 mL×3)
4. washwashed with brine (50 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customto give a residue
9. stirringstirred
10. temperatureat reflux for 3 h
11. customRemoved solvent, purified by flash column chromatography

ORD record

ord-c166ddc0a8bd46f290ca934b3c31373b

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08987461B2