Boron trifluoride → 1-(5-Ethyl-2,4-dihydroxyphenyl)-2-(4-methoxyphenyl)ethanone

HRID 1714833Notes

Reaction equation

HRID 1714833 reaction equation
[CH2:1]([C:3]1[CH:8]=[CH:7][C:6]([OH:9])=[CH:5][C:4]=1[OH:10])[CH3:2].[CH3:11][O:12][C:13]1[CH:18]=[CH:17][C:16]([CH2:19][C:20](O)=[O:21])=[CH:15][CH:14]=1.B(F)(F)F.C([O-])(=O)C.[Na+]>>[CH2:1]([C:3]1[C:4]([OH:10])=[CH:5][C:6]([OH:9])=[C:7]([C:20](=[O:21])[CH2:19][C:16]2[CH:17]=[CH:18][C:13]([O:12][CH3:11])=[CH:14][CH:15]=2)[CH:8]=1)[CH3:2]

Participants

5

Reactant 4

HCID 6356Boron trifluorideHCID 76904-Methoxyphenylacetic AcidHCID 179274-EthylresorcinolHCID 517045Sodium Acetate

Product 1

HCID 7640051-(5-Ethyl-2,4-dihydroxyphenyl)-2-(4-methoxyphenyl)ethanone

Conditions

Temperature
50 °C

Procedure

4-Ethylbenzene-1,3-diol (17.5 g, 159 mmol) and 4-methoxyphenylacetic acid (26.4 g, 159 mmol) was heated with boron trifluoride dietherate solution (100.7 ml, 795 mmol) to 90° C. for 3 hours. The mixture was then cooled to 50° C. before it was added to a stirred solution of 10% aqueous sodium acetate (11). The resulting mixture was stirred at room temperature over night at room temperature. The resulting solid was filtered off dissolved in a minimum volume of methanol and pre-absorbed onto silica gel. For the initial purification the crude material was chromatographed, eluting with an increasingly polar mixture of methylene chloride/methanol (95/5 to 90/10). The fractions containing product were grouped into two groups, evaporated under vacuum to give a solid which was triturated with diethyl ether in a further purification step. The title compound was obtained in three portions of varying purity as an off white solid from combined purest fractions (10.78 g, 26.2%) the less pure fractions (7.56 g, 18.4%) and from the combined, evaporated mother liquors after renewed trituration with iso-hexane/diethylether to give the title product (6.32 g, 15.4%). 1H NMR Spectrum (purest solid): δH (300 MHz, CDCl3) 1.22 (3H t, J=7.5 Hz), 1.63 (1H, s), 2.57 (2H q, J=7.5 Hz), 3.79 (3H, s), 4.16 (2H d, J=3.0 Hz), 5.52 (1H, s), 6.30 (1H, s), 6.85-6.90 (2H, m), 7.16-7.21 (2H, m), 7.59 (1H, s), 12.51 (1H, s); Mass Spectrum: (M+H−) 258.20.

Workup

  1. filtrationThe resulting solid was filtered off
  2. dissolutiondissolved in a minimum volume of methanol
  3. custompre-absorbed onto silica gel
  4. customFor the initial purification the crude material
  5. customwas chromatographed
  6. washeluting with an increasingly polar mixture of methylene chloride/methanol (95/5 to 90/10)
  7. additionThe fractions containing product
  8. customevaporated under vacuum
  9. customto give a solid which
  10. customwas triturated with diethyl ether in a further purification step

Sources & evidence

ORD record
ord-6b883e7d714845dea295ec7ee0c7bcbe
Source dataset
uspto-grants-2010_09
Patent number
US07799781B2

Reaction notes

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