Cesium carbonate → 1,3-Dichloro-2-fluoro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene

HRID 532155Notes

Reaction equation

[Cl:1][C:2]1[CH:3]=[C:4](B2OC(C)(C)C(C)(C)O2)[CH:5]=[C:6]([Cl:9])[C:7]=1[F:8].Br[C:20]([C:22]([F:25])([F:24])[F:23])=[CH2:21].C([O-])([O-])=O.[Cs+].[Cs+]>C1COCC1.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[Cl:9][C:6]1[CH:5]=[C:4]([C:20]([C:22]([F:25])([F:24])[F:23])=[CH2:21])[CH:3]=[C:2]([Cl:1])[C:7]=1[F:8]

Participants

Conditions

Temperature: 70 °C

Procedure

A mixture of 2-(3,5-dichloro-4-fluorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.56 g, 8.83 mmol), 2-bromo-3,3,3-trifluoroprop-1-ene (1.85 g, 10.6 mmol), Cs2CO3 (11.5 mL, 2M, 17.7 mmol) and Pd(PPh3)2Cl2 (200 mg) in THF (30 mL) was heated at 70° C. in a sealed tube for 4 h. The mixture was cooled to rt and partitioned between ether and H2O. The aqueous layer was extracted with EA and the combined organic layers were dried over Na2SO4. The solvent was removed under reduced pressure and the crude product was purified by column chromatography on silica gel eluted with hexanes to give 1,3-dichloro-2-fluoro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene (1.3 g; yield 56%) as colorless oil. 1H NMR (500 MHz, CDCl3): δ 7.412 (d, J=6.5 Hz, 2 H), 6.057 (s, 1 H), 5.806 (s, 1 H) ppm.

Workup

temperatureThe mixture was cooled to rt
custompartitioned between ether and H2O
extractionThe aqueous layer was extracted with EA
dry with materialthe combined organic layers were dried over Na2SO4
customThe solvent was removed under reduced pressure
customthe crude product was purified by column chromatography on silica gel
washeluted with hexanes

Sources & evidence

ORD record: ord-03943589c3a249c4a59da2da6ddc3d61
Source dataset: uspto-grants-2014_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08853186B2

Reaction notes

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