Acetic Anhydride → 1-(2,6-Difluorophenyl)ethan-1-one

HRID 1272570Notes

Reaction equation

C(Cl)(C)(C)C.[Li].[F:7][C:8]1[CH:13]=[CH:12][CH:11]=[C:10]([F:14])[CH:9]=1.FC1C=CC=C(F)C=1[Li].[C:24](OC(=O)C)(=[O:26])[CH3:25]>C1COCC1>[CH3:25][C:24]([C:9]1[C:8]([F:7])=[CH:13][CH:12]=[CH:11][C:10]=1[F:14])=[O:26]

Participants

Conditions

Temperature: -65 °C

Procedure

A solution of tert-butyllithium in THF is firstly produced by reacting 9.25 g of tert-butyl chloride with 1.4 g of lithium granules in 100 g of THF at −78° C. After a conversion of >97% (GC a/a) has been reached, 1,3-difluorobenzene (11.4 g) is added and the mixture is stirred for another 30 minutes at −78° C. and subsequently for 2 hours at −65° C. The resulting solution of 2,6-difluoro-1-lithiobenzene is added dropwise to a solution of 22 g of acetic anhydride in 35 g of THF which has been cooled to −5° C. After the usual aqueous work-up, 2,6-difluoroacetophenone is obtained in a yield of 92%.

Workup

customat −78° C
temperaturehas been cooled to −5° C

Sources & evidence

ORD record: ord-9858a6de778b499d9a7434fdbc7cb869
Source dataset: uspto-grants-2007_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07208614B2

Reaction notes

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