Pyridine → Methyl 5,5,5-trifluoro-3-oxopentanoate

Temperature

0 °C

To a stirred solution of 2,2-dimethyl-[1,3]dioxane-4,6-dione (200 mg, 1.41 mmol), pyridine (0.125 ml, 1.55 mmol) and DMAP (344 mg, 2.81 mmol) in dichloromethane (10 ml), was added 3,3,3-trifluoro-propionyl chloride (0.16 ml, 1.55 mmol) at 0° C. The resulting reaction mixture was stirred under nitrogen for 1 h at 0° C. and then allowed to warm to room temperature and stirred for 2 h. Volatiles were removed under reduced pressure, and the crude residue was diluted with diethyl ether and washed with 1 N HCl. The organic layer was dried and concentrated to get the intermediate, which was diluted with 10 ml of methanol and refluxed for 5 h. Volatiles were removed under reduced pressure to afford the crude 5,5,5-trifluoro-3-oxo-pentanoic acid methyl ester (120 mg, 46%) as brown liquid which was used in the following step without further purification. FIA-MS: 183 (M−H)−.

1. customThe resulting reaction mixture
2. temperatureto warm to room temperature
3. stirringstirred for 2 h
4. customVolatiles were removed under reduced pressure
5. additionthe crude residue was diluted with diethyl ether
6. washwashed with 1 N HCl
7. customThe organic layer was dried
8. concentrationconcentrated
9. customto get the intermediate, which
10. temperaturerefluxed for 5 h
11. customVolatiles were removed under reduced pressure

ORD record

ord-b26c11cd87c34e78aed85d24463854d5

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09199938B2