Tetrahydrofuran → 3-(2-(Trifluoromethyl)phenyl)acrylaldehyde

HRID 2040393Notes

Reaction equation

[F:1][C:2]([F:12])([F:11])[C:3]1[CH:10]=[CH:9][CH:8]=[CH:7][C:4]=1[CH:5]=O.C1C[O:16][CH2:15][CH2:14]1>C(OCC)C.O.[Zn+2].[Br-].[Br-].[Cl-].[Cl-].[Zn+2]>[F:1][C:2]([F:12])([F:11])[C:3]1[CH:10]=[CH:9][CH:8]=[CH:7][C:4]=1[CH:5]=[CH:14][CH:15]=[O:16]

Participants

Conditions

Temperature: 10 °C

Procedure

To a solution of 2-trifluoromethylbenzaldehyde (260 mg) in 5 mL THF was added 200 mg of ZnBr2. With stirring, 400 mg of α,α-bis(trimethylsilyl)-t-butylacetaldimine (7) was added, and stirring was continued overnight. The solution was cooled to 10° C., then hydrolyzed by the addition of a solution of ZnCl2 (200 mg) in diethyl ether/water (3 mL each), followed by stirring at room temperature for 1 h. The solids were removed by filtration through Celite and the filtrate extracted with diethyl ether (2×). The combined ether extracts were washed with water and brine, dried over magnesium sulfate, filtered and concentrated to provide the crude title compound as an oil. The product was purified via silica gel column chromatography to afford a white powder (130 mg): 1H NMR (CDCl3) δ 6.70 (dd, 1H, J=9.6, 4.5 Hz), 7.55 (t, 1H, J=4.5 Hz), 7.63 (t, 1H, J=4.5 Hz), 7.76 (d, 2H, J=4.8 Hz), 7.88 (br d, 1H, J=9.6 Hz), 9.77 (d, 1H, J=4.8 Hz).

Workup

stirringstirring
stirringby stirring at room temperature for 1 h
customThe solids were removed by filtration through Celite
extractionthe filtrate extracted with diethyl ether (2×)
washThe combined ether extracts were washed with water and brine
dry with materialdried over magnesium sulfate
filtrationfiltered
concentrationconcentrated
customto provide the crude title compound as an oil
customThe product was purified via silica gel column chromatography

Sources & evidence

ORD record: ord-7e68f89c4fc244b889db8ece28392378
Source dataset: uspto-grants-2013_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08580834B2

Reaction notes

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