Lithium hydroxide, monohydrate → 4-(2,4-Dichlorophenoxy)butyric acid

HRID 219545Notes

Reaction equation

HRID 219545 reaction equation
[Cl:1][C:2]1[CH:16]=[C:15]([Cl:17])[CH:14]=[CH:13][C:3]=1[O:4][CH2:5][CH2:6][CH2:7][C:8]([O:10]CC)=[O:9].O[Li].O>C1COCC1.O>[Cl:1][C:2]1[CH:16]=[C:15]([Cl:17])[CH:14]=[CH:13][C:3]=1[O:4][CH2:5][CH2:6][CH2:7][C:8]([OH:10])=[O:9]

Participants

5

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 12375252Ethyl 4-(2,4-dichloro-phenoxy)butanoate

Product 1

HCID 14894-(2,4-Dichlorophenoxy)butyric acidYield 74.3%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of ethyl 4-(2,4-dichlorophenoxy)-butyrate (57 g, crude from last step, about 0.2 mol) in THF (500 mL) and water (500 mL) was added LiOH.H2O (12.6 g, 0.3 mol), and the reaction mixture was stirred for 5 h at RT. The mixture was washed with Et2O (3×200 mL), and the aqueous layer was acidified by addition of HCl (20%) to pH ˜2. The mixture was extracted with EtOAc (3×400 mL), the combined organic extracts were washed with water and brine, dried over Na2SO4 and concentrated in vacuo to give the butyric acid (37 g, 74.3% from 2,4-dichlorophenol) as a white solid. 1H-NMR (CDCl3): δ 7.36 (d, 1H, J=8.8 Hz), 7.18 (dd, 1H, J1=8.8 Hz, J2=2.4 Hz), 6.84 (d, 1H, J=8.8 Hz), 4.07 t, 2H, J=7.2 Hz), 2.64 (t, 2H, J=7.2 Hz), 2.17 (p, 2H, J=6.4 Hz).

Workup

  1. washThe mixture was washed with Et2O (3×200 mL)
  2. additionthe aqueous layer was acidified by addition of HCl (20%) to pH ˜2
  3. extractionThe mixture was extracted with EtOAc (3×400 mL)
  4. washthe combined organic extracts were washed with water and brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-e2b2472d77d94f4d81b8723ee811018c
Source dataset
uspto-grants-2012_06
Patent number
US08202861B2

Reaction notes

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