Acetic Acid → 2,2-Dibromo-1-[4-(trifluoromethyl)phenyl]ethanone

This compound was synthesised by the general procedure represented in Scheme 2, a stirred solution of 1-(4-trifluoromethyl-phenyl)-ethanone (1 g, 5.3 mmol) ) and acetic acid (50 ml) was refluxed 1 h, then bromine (0.35 ml, 6.9 mmol) was added dropwise and the mixture refluxed 3 h. After cooling at room temperature, water (50 ml) was added and the mixture extracted with CH2Cl2 (50 ml), the organic layer was washed with water (50 ml), a solution of NaHCO3 saturated (50 ml) and finally with NaCl solution (50 ml), the organic layer was dried over sodium sulphate and the solvent evaporated under reduced pressure. The resulting residue was purified by column chromatography, using a mixture of ethyl acetate:hexane (1:8) as eluent giving two compounds, the titled compound 41 as a yellow solid (45%) m.p.: 40-41° C., 1H-NMR (CDCl3): δ8.2 (d, J=8.3 Hz, 2H, Ar), 7.8 (d, J=8.3 Hz, 2H, Ar), 6.6 (s, 1H, CH); 13C-NMR (CDCl3): δ184.1 (CO), 134.7 (q, J=272.9 Hz, C—CF3), 132.7 (C—CO), 129.2 (CH), 124.8 (CH), 119.5 (q, J=33.09, CF3), 38.2 (CH); M/z (EI): 348, 346, 344 (M+, 1, 6, 1%), 173 (M-CHBr2, 100%); HPLC: Column μ Bondapack C18, 5 μm, 300 A, (300×3.9 mm), Purity 97%, r.t.=9.96 min, acetonitrile/H2O (0.05% H3PO4+0.04% Et3N) 50/50. The second compound was identified as 2-bromo-1-(4-trifluoromethyl-phenyl)-ethanone (0,6%), described as the example 40.

1. customThis compound was synthesised by the general procedure
2. temperaturethe mixture refluxed 3 h
3. extractionthe mixture extracted with CH2Cl2 (50 ml)
4. washthe organic layer was washed with water (50 ml)
5. dry with materiala solution of NaHCO3 saturated (50 ml) and finally with NaCl solution (50 ml), the organic layer was dried over sodium sulphate
6. customthe solvent evaporated under reduced pressure
7. customThe resulting residue was purified by column chromatography
8. additiona mixture of ethyl acetate:hexane (1:8) as eluent
9. customgiving two compounds

ORD-Eintrag

ord-111ac77bdba34578bbd5644f2a94a6b3

Quelldatensatz

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06747057B2