Bromine → Ethyl 5-oxocyclopent-1-ene-1-heptanoate

HRID 1580339Notes

Reaction equation

HRID 1580339 reaction equation
BrBr.C([C:8]1([CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][C:20]([O:22][CH2:23][CH3:24])=[O:21])[CH2:12][CH2:11][CH2:10][C:9]1=[O:13])(OCC)=O>C(Cl)(Cl)Cl>[C:20]([CH2:19][CH2:18][CH2:17][CH2:16][CH2:15][CH2:14][C:8]1[C:9](=[O:13])[CH2:10][CH2:11][CH:12]=1)([O:22][CH2:23][CH3:24])=[O:21]

Participants

4

Reactant 2

HCID 24408BromineHCID 13046295Ethyl 1-(7-ethoxy-7-oxoheptyl)-2-oxocyclopentane-1-carboxylate

Product 1

HCID 15573491Ethyl 5-oxocyclopent-1-ene-1-heptanoate

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

Under agitation at 20° , 48 g. of Br2, dissolved in 500 ml. of CHCl3, is added dropwise within 2 hours to a solution of 100 g. of 2-carbethoxy-2-(6-carbethoxyhexyl)-cyclopentanone in 1 l. of CHCl3. The solvent is distilled off, the residue is taken up in a mixture of 4 l. of ethanol, l kg. of H2SO4 (density: 1.84), and 100 ml. of H2O, refluxed for 18 hours under N2 and poured on 10 kg. of ice after cooling. The reaction mixture is extracted three times with respectively 5 l. of ether, the combined ether extracts are dried over Na2SO4, the solvent is distilled off, and chromatographic purification of the residue (silica gel/petroleum ether : ether =1 : 1) yields 2-(6-carbethoxyhexyl)- 2-cyclopentenone.

Workup

  1. customat 20°
  2. distillationThe solvent is distilled off
  3. additionthe residue is taken up in a mixture of 4 l
  4. temperatureof H2O, refluxed for 18 hours under N2
  5. additionpoured on 10 kg
  6. temperatureof ice after cooling
  7. extractionThe reaction mixture is extracted three times with respectively 5 l
  8. dry with materialof ether, the combined ether extracts are dried over Na2SO4
  9. distillationthe solvent is distilled off
  10. customchromatographic purification of the residue (silica gel/petroleum ether : ether =1 : 1)

Sources & evidence

ORD record
ord-ced21b41f9bd41ec99cfe74a254e19b8
Source dataset
uspto-grants-1976_01
Patent number
US03932487

Reaction notes

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