Boronic Acid → Ethyl 5,5,5-trifluoro-4-oxopentanoate

Temperature

170 °C

In a one-necked round-bottomed flask equipped with a distillation head and cooler, a mixture of 2-(2,2,2-trifluoro-acetyl)-succinic acid diethyl ester (54.6 g, 202 mmol) and boronic acid (12.5 g, 202 mmol) is heated to 170° C. Heating is continued for4 h, during which time ethanol is gradually distilled off as it is formed. After cooling to room temperature, the reaction mixture is poured onto ice and extracted twice with EtOAc. The combined organic layers are washed with brine, dried over Na2SO4 and concentrated at reduced pressure to afford a brown oil. The crude product is purified by distillation (60° C., 10 mbar) to afford the title compound as a colorless liquid (17.3 g, 87.3 mmol, 43%). 1H NMR (400 MHz, CDCl3, 298 K): δ=4.15 (q, J=7.1 Hz, 2H), 3.02 (t, J=6.4 Hz, 2H), 2.70 (t, J=6.4 Hz, 2H), 1.45 (t, J=7.1 Hz, 3H). MS (ES+): 199 (M(C7H9F3O3)+H)+.

1. customIn a one-necked round-bottomed flask equipped with a distillation head and cooler
2. temperatureHeating
3. distillationis gradually distilled off as it
4. customis formed
5. temperatureAfter cooling to room temperature
6. additionthe reaction mixture is poured onto ice
7. extractionextracted twice with EtOAc
8. washThe combined organic layers are washed with brine
9. dry with materialdried over Na2SO4
10. concentrationconcentrated at reduced pressure
11. customto afford a brown oil
12. distillationThe crude product is purified by distillation (60° C., 10 mbar)

ORD record

ord-90be355142b34bdc87e73564076c5443

Source dataset

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08193236B2