Acetic Acid → Methyl 2-methyl-1-benzofuran-7-carboxylate

HRID 1761928Notes

Reaction equation

HRID 1761928 reaction equation
[OH:1][C:2]1[C:11]([CH:12]=[C:13]([N+]([O-])=O)[CH3:14])=[CH:10][CH:9]=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].C(O)(=O)C>[Fe].C1(C)C=CC=CC=1>[CH3:14][C:13]1[O:1][C:2]2[C:3]([C:4]([O:6][CH3:7])=[O:5])=[CH:8][CH:9]=[CH:10][C:11]=2[CH:12]=1

Participants

5

Reactant 2

HCID 176Acetic AcidHCID 53867347Methyl 2-hydroxy-3-(2-nitro-1-propenyl)benzoate

Product 1

HCID 14229729Methyl 2-methyl-1-benzofuran-7-carboxylateYield 76.6%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 1140TolueneSolvent

Conditions

Temperature
70 °C

Procedure

A mixture of 2.02 g of methyl 2-hydroxy-3-(2-nitro-1-propenyl)benzoate, 4.75 g of iron powder and 40 ml of acetic acid is heated at 70° C. for 25 minutes. Toluene is added to the reaction mixture, and the mixture is filtered and washed with chloroform. The washings and the filtrate are combined and the mixture is evaporated under reduced pressure to remove solvent. 50 ml of toluene, 2.43 g of p-toluenesulfonic acid monohydrate and 1 ml of water are added to the residue. The mixture is refluxed for 50 minutes and further refluxed 20 minutes while removing water azeotropically. Ethyl acetate is added to the reaction mixture. The mixture is washed successively with water and an aqueous saturated sodium bicarbonate solution, dried and evaporated to remove solvent. The residue is purified by silica gel column chromatography to give 1.24 g of methyl 2-methylbenzofuran-7-carboxylate as colorless oil.

Workup

  1. filtrationthe mixture is filtered
  2. washwashed with chloroform
  3. customthe mixture is evaporated under reduced pressure
  4. customto remove solvent
  5. addition50 ml of toluene, 2.43 g of p-toluenesulfonic acid monohydrate and 1 ml of water are added to the residue
  6. temperatureThe mixture is refluxed for 50 minutes
  7. temperaturefurther refluxed 20 minutes
  8. customwhile removing water azeotropically
  9. additionEthyl acetate is added to the reaction mixture
  10. washThe mixture is washed successively with water
  11. dry with materialan aqueous saturated sodium bicarbonate solution, dried
  12. customevaporated
  13. customto remove solvent
  14. customThe residue is purified by silica gel column chromatography

Sources & evidence

ORD record
ord-3da17d70805b45ec85343e11d7cf61cc
Source dataset
uspto-grants-1989_05
Patent number
US04829067

Reaction notes

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