Hydrochloric Acid → 3-(2-Pyridyl)-2-cyclopenten-1-one

HRID 655136Notes

Reaction equation

HRID 655136 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.[Li]CCCC.C([O:15][C:16]1[CH2:20][CH2:19][C:18](=O)[CH:17]=1)C.Cl>C1COCC1>[N:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[C:18]1[CH2:19][CH2:20][C:16](=[O:15])[CH:17]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 79732-BromopyridineHCID 897773-Ethoxycyclopent-2-en-1-oneHCID 178418339Butyllithium

Product 1

HCID 392355473-(2-Pyridyl)-2-cyclopenten-1-oneYield 62%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 2-Bromopyridine (5.00 g, 31.6 mmol) in THF (30 ml) was added dropwise n-BuLi (2.55 M in Hexane, 12.5 mL. 31.9 mmol) at −78° C., and stirred for 10 min. To a reaction mixture was added dropwise 3-ethoxy-2-cyclopentenone (2.00 g, 15.9 mmol) in THF (10 mL) at −78° C., and stirred at 0° C. for 2 h. The reaction mixture was acidified with 2M HCl (10 mL), and aqueous layer was washed with EtOAc. The aqueous layer was basified with 1M NaOH aq., and then extracted with CH2Cl2. The organic layer was washed with brine, and dried over anhyd Na2SO4 followed by the removal of solvent. The crude product was purified by column chromatography (Hexane/EtOAc=1/3) to yield 3-(2-pyridyl)-2-cyclopenten-1-one (1.57 g, 58%) as brown solid.

Workup

  1. stirringstirred at 0° C. for 2 h
  2. washwas washed with EtOAc
  3. extractionextracted with CH2Cl2
  4. washThe organic layer was washed with brine
  5. dry with materialdried over anhyd Na2SO4
  6. customfollowed by the removal of solvent
  7. customThe crude product was purified by column chromatography (Hexane/EtOAc=1/3)

Sources & evidence

ORD record
ord-c46e860a09db44bf83a44588dea15a21
Source dataset
uspto-grants-2011_12
Patent number
US08071591B2

Reaction notes

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