Lithium Hydroxide → 5-(2,5-Dichlorophenyl)pentanoic acid

HRID 1532551Notes

Reaction equation

HRID 1532551 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[CH2:9][CH2:10][CH2:11][CH2:12][C:13]([O:15]C)=[O:14].[Li+].[OH-]>O1CCCC1.CO>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[CH2:9][CH2:10][CH2:11][CH2:12][C:13]([OH:15])=[O:14]

Participants

5

Reactant 2

HCID 3939Lithium HydroxideHCID 22013526Methyl 5-(2,5-Dichlorophenyl)pentanoate

Product 1

HCID 220135385-(2,5-Dichlorophenyl)pentanoic acidYield 70%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

Methyl 5-(2,5-dichlorophenyl)pentanoate (1.10 g, 4.2 mmol) was dissolved in 20 ml tetrahydrofuran and 7 ml methanol. 1 N LiOH (12 ml) was added dropwise and the reaction was stirred at room temperature for 2 days. The reaction was worked-up by acidification with 2 N HCl and removal of most of the tetrahydrofuran and methanol on a rotary evaporator followed by extraction of the aqueous residue with ethyl acetate. The organic phase was washed with water and saturated brine, dried over anhydrous sodium sulfate and concentrated to a residue. Flash chromatogaphy (silica gel; hexane/toluene (19/1) with 1% acetic acid) of the residue gave 725 mg (70%) of a white solid. 1H NMR (200 MHz, CD3OD) delta=7.30-7.26 (m, H3, H6), 7.14 (dd, J=2.6, 8.4 Hz, H4), 2.70 (t, J=7.2 Hz, Ar—CH2—), 2.30 (t, J=7.0 Hz, —CH2—COOH), 1.67-1.57 (m, —CH2—CH2—CH2—CH2—); MS (EI, m/z (relative intensity)) 248 (29), 246 (M+, 45), 167 (31), 165 (97), 161 (66), 159 (100); exact mass calculated for C11H12Cl2O2, [M]+ 246.0213, found 246.0210.

Workup

  1. customThe reaction was worked-up by acidification with 2 N HCl and removal of most of the tetrahydrofuran and methanol
  2. customon a rotary evaporator
  3. extractionfollowed by extraction of the aqueous residue with ethyl acetate
  4. washThe organic phase was washed with water and saturated brine
  5. dry with materialdried over anhydrous sodium sulfate
  6. concentrationconcentrated to a residue

Sources & evidence

ORD record
ord-8be5e65b9574472bb3cb3b8a0adb31d0
Source dataset
uspto-grants-2001_03
Patent number
US06204005B1

Reaction notes

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