Lithium Hydroxide → 4-Acetamido-5-chloro-2-methoxybenzoic acid

HRID 1861258Notes

Reaction equation

HRID 1861258 reaction equation
C[O:2][C:3](=[O:17])[C:4]1[CH:9]=[C:8]([Cl:10])[C:7]([NH:11][C:12](=[O:14])[CH3:13])=[CH:6][C:5]=1[O:15][CH3:16].[Li+].[OH-]>CO>[C:12]([NH:11][C:7]1[C:8]([Cl:10])=[CH:9][C:4]([C:3]([OH:17])=[O:2])=[C:5]([O:15][CH3:16])[CH:6]=1)(=[O:14])[CH3:13]

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 77721Methyl 4-acetamido-5-chloro-2-methoxybenzoate

Product 1

HCID 109884964-Acetamido-5-chloro-2-methoxybenzoic acidYield 50%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

4-Acetylamino-5-chloro-2-methoxy-benzoic acid methyl ester (2.09 g, 8.11 mmol) was dissolved in MeOH (110 ml) and LiOH solution (25.48 mmol in 30 ml, 1:1 MeOH:H2O) added and the solution stirred at room temperature for 6 hours. The solvent was concentrated in vacuo, EtOAc added and the organic phase was washed with 0.5N HCl then extracted with saturated NaHCO3 (2×). The aqueous phase was acidified with 12N HCl to pH 1 and the resulting precipitate extracted into CH2Cl2. The combined extracts were dried over anhydrous Na2SO4, filtered and evaporated to give the title compound as a white solid (0.933 g, 50% yield). 1H-NMR (500 MHz, CDCl3) δ 2.31 (s, 3H), 4.10 (s, 3H), 7.78-7.92 (br s, 1H), 8.17 (s, 1H), 8.45 (s, 1H). Analytical HPLC 5.62 min.

Workup

  1. concentrationThe solvent was concentrated in vacuo, EtOAc
  2. additionadded
  3. washthe organic phase was washed with 0.5N HCl
  4. extractionthen extracted with saturated NaHCO3 (2×)
  5. extractionthe resulting precipitate extracted into CH2Cl2
  6. dry with materialThe combined extracts were dried over anhydrous Na2SO4
  7. filtrationfiltered
  8. customevaporated

Sources & evidence

ORD record
ord-71be8402ec5940838050516047d59f0b
Source dataset
uspto-grants-2003_03
Patent number
US06531474B1

Reaction notes

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