Ethanol → HCID 57718928, compound

HRID 1985240Notes

Reaction equation

HRID 1985240 reaction equation
C[O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2([C:14]([OH:16])=[O:15])[CH2:13][CH2:12][CH2:11][CH2:10]2)=[CH:5][CH:4]=1.OS(O)(=O)=O.B(Br)(Br)Br.[CH2:26](O)[CH3:27]>C(Cl)Cl>[CH2:26]([O:16][C:14]([C:9]1([C:6]2[CH:7]=[CH:8][C:3]([OH:2])=[CH:4][CH:5]=2)[CH2:13][CH2:12][CH2:11][CH2:10]1)=[O:15])[CH3:27]

Participants

6

Reactant 4

HCID 702EthanolHCID 1118Sulfuric AcidHCID 25134Boron tribromideHCID 986301-(4-Methoxyphenyl)cyclopentane-1-carboxylic acid

Product 1

HCID 57718928HCID 57718928, compoundYield 79%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of 1-(p-methoxyphenyl)-cyclopentanecarboxylic acid 093909 (5.0 g, 22.7 mmol) in ethanol (50 mL) was treated with conc. H2SO4 (4.40 g, 44.9 mmol) and heated to reflux under N2 for 12 h. The reaction was cooled and the solvent removed in vacuo to give a residue that was extracted with EtOAc and water. The organic layer was dried (MgSO4) and the solvent removed in vacuo to 5.93 g crude ester (100%) that was utilized without purification. The ester (5.93 g, assume 22.7 mmol) was dissolved in dry CH2Cl2 (75 mL), cooled to −78° C. and then treated dropwise with BBr3 (11.4 g, 45.6 mmol). The reaction was warmed to 0° C. for 15 minutes and then quenched with methanol then water. The reaction mixture was extracted with CH2Cl2 and water, the organic layer was dried (MgSO4), and the solvent removed in vacuo to give crude product that was purified by flash chromatography using 6:1 hexanes:EtOAc to afford 4.34 g (79%) 1-(4-hydroxy-phenyl)-cyclopentanecarboxylic acid ethyl ester. MS (ES+) Calc'd for C14H19O3 (M+1) 235. Found m/z 235 (100%). 1H NMR.

Workup

  1. temperatureheated
  2. temperatureto reflux under N2 for 12 h
  3. temperatureThe reaction was cooled
  4. customthe solvent removed in vacuo
  5. customto give a residue that
  6. extractionwas extracted with EtOAc and water
  7. dry with materialThe organic layer was dried (MgSO4)
  8. customthe solvent removed in vacuo to 5.93 g crude ester (100%) that
  9. customwas utilized without purification
  10. temperatureThe reaction was warmed to 0° C. for 15 minutes
  11. customquenched with methanol
  12. extractionThe reaction mixture was extracted with CH2Cl2 and water
  13. dry with materialthe organic layer was dried (MgSO4)
  14. customthe solvent removed in vacuo
  15. customto give crude product that
  16. customwas purified by flash chromatography

Sources & evidence

ORD record
ord-f146735fc22e4745b23a1c7c60cf9f11
Source dataset
uspto-grants-2009_06
Patent number
US07544812B2

Reaction notes

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