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

HRID 402904Notes

Reaction equation

HRID 402904 reaction equation
C(OC(=O)[CH:5]([C:12](=[O:17])[C:13]([F:16])([F:15])[F:14])[CH2:6][C:7]([O:9][CH2:10][CH3:11])=[O:8])C.B(O)O>C(O)C>[CH2:10]([O:9][C:7](=[O:8])[CH2:6][CH2:5][C:12](=[O:17])[C:13]([F:16])([F:15])[F:14])[CH3:11]

Participants

4

Reactant 2

HCID 61668Boronic AcidHCID 11346247Butanedioic acid, (trifluoroacetyl)-, diethyl ester

Product 1

HCID 13379932Ethyl 5,5,5-trifluoro-4-oxopentanoateYield 43.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
170 °C

Procedure

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 for 4 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)+.

Workup

  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)

Sources & evidence

ORD record
ord-715a9f1dc86d4bf6b8c027be82a75155
Source dataset
uspto-grants-2014_06
Patent number
US08742132B2

Reaction notes

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