Acetic Acid → Methyl 6-methoxynaphthalene-2-acetate

HRID 1576452Notes

Reaction equation

HRID 1576452 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9](=O)[CH2:8][CH2:7][CH2:6]2.[C:14](=O)(OCC)[O:15][CH2:16][CH3:17].[H-].[Na+].[H][H].C(O)(=[O:28])C>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[CH:9]=[C:8]([CH2:17][C:16]([O:15][CH3:14])=[O:28])[CH:7]=[CH:6]2

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 7766Diethyl CarbonateHCID 141126-Methoxy-alpha-tetraloneHCID 24758Sodium hydrideHCID 178418361HCID 178418361, compound

Product 1

HCID 90324Methyl 6-methoxynaphthalene-2-acetate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 18 g. of 6-methoxy-1-tetralone, 60 g. of diethyl carbonate, 2.5 g. of sodium hydride, and 200 ml. of toluene is heated to 60°C for 5 hours. The mixture is cooled, acidified by the addition of 200 ml. of 1N hydrochloric acid, and then extracted with three 75 ml. portions of benzene. The extracts are combined, washed with water to neutrality, and dried over sodium sulfate. The mixture, containing 6-methoxy-2-ethoxycarbonyl-1-tetralone, is treated with 2.5 g. of sodium hydride at room temperature with stirring. Twenty grams of ethyl α-bromoacetate are then added and the mixture is allowed to stand for 12 hours at room temperature. The mixture is added to 500 ml. of water and extracted with methylene chloride. The extracts are combined, washed with water to neutrality, dried over sodium sulfate, and evaorated. The residue, containing 6-methoxy-2-ethoxycarbonyl-2-(ethoxycarbonylmethyl)-1-tetralone, is refluxed in 200 ml. of 6N hydrochloric acid for 24 hours and then the reflux mixture is evaporated. The residue, containing 6-methoxy-2-(carboxymethyl)-1-tetralone, is reduced by treating it with 200 ml. of ethanol containing 8 g. of sodium borohydride. After one hour, the mixture is acidified with the addition of 100 ml. of 3N hydrochloric acid, and the resulting mixture is extracted with several portions of methylene chloride. The extracts are combined, washed with water to neutrality, dried over sodium sulfate, and evaporated. The esidue, containing 6-methoxy-1-hydroxy-1,2,3,4-tetrahydro-2-naphthylacetic acid, is hydrogenolyzed by hydrogenating with one equivalent of hydrogen in acetic acid containing 300 mg. of 5% palladium-on-barium sulfate. The hydrogenation mixture is filtered and evaporated. The residue, containing 6-methoxy-1,2,3,4-tetrahydro-2-naphthylacetic acid, is dissolved in 200 ml. of diethyl ether and the mixture is then added to a 100 ml. solution of diethyl ether containing 4 g. of diazomethane. The mixture is then evaporated to dryness. The esterified residue is dehydrogenated by adding it to 1 g. of 10% palladium-on-charcoal and heating the resulting mixture for six hours at 200°C. The cooled mixture is diluted with 200 ml. of chloroform, filtered, and evaporated to afford methyl 6-methoxy-2-naphthylacetate.

Workup

  1. additionA mixture of 18 g
  2. temperatureThe mixture is cooled
  3. additionacidified by the addition of 200 ml
  4. extractionof 1N hydrochloric acid, and then extracted with three 75 ml
  5. washwashed with water to neutrality
  6. dry with materialdried over sodium sulfate
  7. additionThe mixture, containing 6-methoxy-2-ethoxycarbonyl-1-tetralone
  8. additionis treated with 2.5 g
  9. additionTwenty grams of ethyl α-bromoacetate are then added
  10. additionThe mixture is added to 500 ml
  11. extractionof water and extracted with methylene chloride
  12. washwashed with water to neutrality
  13. dry with materialdried over sodium sulfate
  14. additionThe residue, containing 6-methoxy-2-ethoxycarbonyl-2-(ethoxycarbonylmethyl)-1-tetralone
  15. temperatureis refluxed in 200 ml
  16. waitof 6N hydrochloric acid for 24 hours
  17. customthe reflux mixture is evaporated
  18. additionThe residue, containing 6-methoxy-2-(carboxymethyl)-1-tetralone
  19. additionby treating it with 200 ml
  20. waitAfter one hour
  21. additionthe mixture is acidified with the addition of 100 ml
  22. extractionof 3N hydrochloric acid, and the resulting mixture is extracted with several portions of methylene chloride
  23. washwashed with water to neutrality
  24. dry with materialdried over sodium sulfate
  25. customevaporated
  26. additionThe esidue, containing 6-methoxy-1-hydroxy-1,2,3,4-tetrahydro-2-naphthylacetic acid
  27. filtrationThe hydrogenation mixture is filtered
  28. customevaporated
  29. additionThe residue, containing 6-methoxy-1,2,3,4-tetrahydro-2-naphthylacetic acid
  30. dissolutionis dissolved in 200 ml
  31. additionof diethyl ether and the mixture is then added to a 100 ml
  32. customThe mixture is then evaporated to dryness
  33. additionby adding it to 1 g
  34. temperatureof 10% palladium-on-charcoal and heating the resulting mixture for six hours at 200°C
  35. additionThe cooled mixture is diluted with 200 ml
  36. filtrationof chloroform, filtered
  37. customevaporated

Sources & evidence

ORD record
ord-86968f676909478ca1bd1e1b452afb86
Source dataset
uspto-grants-1976_09
Patent number
US03980699

Reaction notes

Loading…