Ethyl acetate hexane → 5-Chloro-6-methoxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester

HRID 493219Notes

Reaction equation

HRID 493219 reaction equation
[CH2:1]([O:3][C:4](=[O:19])[CH2:5][O:6][C:7]1[CH:12]=[C:11]([O:13][CH3:14])[C:10]([Cl:15])=[CH:9][C:8]=1[C:16](=O)[CH3:17])[CH3:2].CC([O-])(C)C.[K+].CCCCCC.CCOC(C)=O>C(COC)OC>[CH2:1]([O:3][C:4]([C:5]1[O:6][C:7]2[CH:12]=[C:11]([O:13][CH3:14])[C:10]([Cl:15])=[CH:9][C:8]=2[C:16]=1[CH3:17])=[O:19])[CH3:2]

Participants

5

Reactant 3

HCID 21226206Ethyl acetate hexaneHCID 23665647Potassium tert-butoxideHCID 68726576(2-Acetyl-4-chloro-5-methoxy-phenoxy)-acetic acid ethyl ester

Product 1

HCID 687269975-Chloro-6-methoxy-3-methyl-benzofuran-2-carboxylic acid ethyl esterYield 40.9%

Reagents, catalysts & solvents 1

HCID 80711,2-DimethoxyethaneSolvent

Procedure

The above prepared (2-acetyl-4-chloro-5-methoxy-phenoxy)-acetic acid ethyl ester-(6.05 g, 21.1 mmol) was dissolved in 45 mL of dimethoxyethane and treated at −15° C. with KOtBu (0.947 g, 0.4 eq.). After keeping for 45 Min. at −15° C. and 5 h at 0° C., the reaction mixture was poured onto crashed ice/HCl, twofold extracted with AcOEt, washed with water, dried over magnesium sulfate, and evaporated to dryness to leave 5.26 g of crude product. Flash chromatography (SiO2, hexane/AcOEt=9/1) of the latter afforded 2.32 g of the title compound as white crystals.

Workup

  1. additionat −15° C. and 5 h at 0° C., the reaction mixture was poured
  2. extractiontwofold extracted with AcOEt
  3. washwashed with water
  4. dry with materialdried over magnesium sulfate
  5. customevaporated to dryness
  6. customto leave 5.26 g of crude product

Sources & evidence

ORD record
ord-509d6a58167443e2981b699528bb029c
Source dataset
uspto-grants-2009_05
Patent number
US07534788B2

Reaction notes

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