Methanol → 2-Carbomethoxy 4,5-dichlorobenzoic acid

HRID 84936

Reaction equation

HRID 84936 reaction equation
[H-].[Na+].[Cl:3][C:4]1[CH:5]=[C:6]2[C:11](=[O:12])[O:10][C:8](=[O:9])[C:7]2=[CH:13][C:14]=1[Cl:15].[CH3:16][OH:17]>>[Cl:15][C:14]1[C:4]([Cl:3])=[CH:5][C:6]([C:11]([OH:10])=[O:12])=[C:7]([C:8]([O:17][CH3:16])=[O:9])[CH:13]=1

Participants

4

Reactant 3

HCID 887Methanol2×HCID 24758Sodium hydrideHCID 703344,5-Dichlorophthalic anhydride

Product 1

HCID 198042632-Carbomethoxy 4,5-dichlorobenzoic acid

Procedure

To methanol (200 mL) was added sodium hydride (2.72 g, 60% dispersion, 68.0 mmol) portionwise under nitrogen at ambient temperature. To the solution was then added a solution of 4,5-dichlorophthalic anhydride (5.90 g, 27.2 mmol) in methanol (50 mL) dropwise under nitrogen at room temperature. The reaction was stirred for one hour and then concentrated to remove the methanol. The residue was taken up in aqueous 10% potassium carbonate solution and extracted with ethyl acetate (2×). The aqueous portion was acidified to pH 2 with 10% hydrochloric acid and extracted with ethyl acetate (3×), dried (Na2SO4) and concentrated to afford the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 3.81 (s, 3H) 7.94-8.01 (m, 2H) 13.60-13.70 (br, 1H); MS (+DCI/NH3) m/z 266.0 [M+NH4]+.

Workup

  1. concentrationconcentrated
  2. customto remove the methanol
  3. extractionextracted with ethyl acetate (2×)
  4. extractionextracted with ethyl acetate (3×)
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-cc34bf9a49cd4cf5a4feb831c77785a6
Source dataset
uspto-grants-2014_09
Patent number
US08846951B2

Linked notes

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