HCID 20163689, compound → HCID 86741844, compound

HRID 256343Notes

Reaction equation

HRID 256343 reaction equation
[OH:1][C:2]1[C:6]2[CH:7]=[C:8]([O:11][CH3:12])[CH:9]=[CH:10][C:5]=2[O:4][C:3]=1[C:13]([O:15][CH3:16])=[O:14].[C:17]1([CH2:23]OOC(=NC(C)C)NC(C)C)[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>C(#N)C>[CH3:12][O:11][C:8]1[CH:9]=[CH:10][C:5]2[O:4][C:3]([C:13]([O:15][CH3:16])=[O:14])=[C:2]([O:1][CH2:23][C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)[C:6]=2[CH:7]=1

Participants

4

Reactant 2

HCID 20163689HCID 20163689, compoundHCID 54732577Methyl 3-hydroxy-5-methoxy-1-benzofuran-2-carboxylate

Product 1

HCID 86741844HCID 86741844, compoundYield 64%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of 8.0 g (0.036 mole) of 3-hydroxy-5-methoxy-2-benzofurancarboxylic acid, methyl ester and 10.0 g (0.043 mole) of O-phenylmethoxy-N,N'-diisopropylisourea (L. J. Mathias, Synthesis, 561 (1979)) in 200 ml of acetonitrile is stirred at reflux under a nitrogen atmosphere for 22 hours. The mixture is cooled and filtered to remove by-product 1,3-diisopropylurea. The insoluble material is washed with hexane and the combined filtrates are evaporated (vacuum). The residue is treated with 250 ml of diethyl ether, and the mixture is again filtered and evaporated. The crude oil residue is chromatographed over silica gel using dichloromethane/hexane (2:1) elution to obtain 7.2 g 64% yield) of the purified 5-methoxy-3-(phenylmethoxy)2-benzofurancarboxylic acid, methyl ester as an oil. The ester is saponified without additional purification.

Workup

  1. temperatureat reflux under a nitrogen atmosphere for 22 hours
  2. temperatureThe mixture is cooled
  3. filtrationfiltered
  4. customto remove by-product 1,3-diisopropylurea
  5. washThe insoluble material is washed with hexane
  6. customthe combined filtrates are evaporated (vacuum)
  7. additionThe residue is treated with 250 ml of diethyl ether
  8. filtrationthe mixture is again filtered
  9. customevaporated
  10. customThe crude oil residue is chromatographed over silica gel
  11. washdichloromethane/hexane (2:1) elution

Sources & evidence

ORD record
ord-1ff569bc6d064ae8aa6bd2a4508ac359
Source dataset
uspto-grants-1987_10
Patent number
US04703053

Reaction notes

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