Benzene → HCID 18787507, compound

HRID 1107520Notes

Reaction equation

HRID 1107520 reaction equation
[CH3:1][C:2]1[O:3][C:4]2[C:11]([CH:12]=O)=[CH:10][CH:9]=[CH:8][C:5]=2[C:6]=1[CH3:7].[CH2:14]([NH:16][CH2:17][CH3:18])[CH3:15].[CH:19]1C=CC=CC=1>>[CH3:1][C:2]1[O:3][C:4]2[C:11]([CH:12]([N:16]([CH2:17][CH3:18])[CH2:14][CH3:15])[CH3:19])=[CH:10][CH:9]=[CH:8][C:5]=2[C:6]=1[CH3:7]

Participants

4

Reactant 3

HCID 241BenzeneHCID 8021DiethylamineHCID 10855983HCID 10855983, compound

Product 1

HCID 18787507HCID 18787507, compoundYield 11%

Procedure

1.8 g (10.3 mmol) of 2,3-dimethyl-7 -formylbenzofuran, 80 ml of benzene, 4A molecular sieve and 3.19 ml (30.8 mmol) of diethylamine are introduced into a 250 ml three-necked flask equipped with a reflux condenser. The mixture is heated at reflux for 16 hours, cooled to room temperature and then filtered to remove the molecular sieve. The filtrate is concentrated under vacuum and is introduced, with 100 ml of anhydrous tetrahydrofuran, into a 250 ml three-necked flask equipped with a reflux condenser. The solution is cooled to 0° C. by an ice bath and 20 ml of a 3.0 molar solution of methylmagnesium bromide in tetrahydrofuran are added. The reaction mixture is heated at reflux for 26 hours, 8 ml of a 3.0 molar solution of methylmagnesium bromide in tetrahydrofuran are again added and stirring is continued under reflux for 12 hours. The mixture is cooled by an ice bath, 50 ml of a saturated ammonium chloride solution are added and extraction is carried out with ethyl acetate (3×200 ml). The organic phases are combined, dried over magnesium sulphate and concentrated under vacuum. The residue is purified by chromatography on a silica column (elution solvent: 5% methanol in dichloromethane). 0.281 g (Yield: 11%) of 2,3-dimethyl-7-[1-(diethylamino)ethyl]benzofuran is obtained in the form of a colourless oil.

Workup

  1. customequipped with a reflux condenser
  2. temperatureThe mixture is heated
  3. temperatureat reflux for 16 hours
  4. filtrationfiltered
  5. customto remove the molecular sieve
  6. concentrationThe filtrate is concentrated under vacuum
  7. additionis introduced, with 100 ml of anhydrous tetrahydrofuran, into a 250 ml three-necked flask
  8. customequipped with a reflux condenser
  9. temperatureThe solution is cooled to 0° C. by an ice bath
  10. addition20 ml of a 3.0 molar solution of methylmagnesium bromide in tetrahydrofuran are added
  11. temperatureThe reaction mixture is heated
  12. temperatureat reflux for 26 hours
  13. addition8 ml of a 3.0 molar solution of methylmagnesium bromide in tetrahydrofuran are again added
  14. temperatureunder reflux for 12 hours
  15. temperatureThe mixture is cooled by an ice bath
  16. addition50 ml of a saturated ammonium chloride solution are added
  17. extractionextraction
  18. dry with materialdried over magnesium sulphate
  19. concentrationconcentrated under vacuum
  20. customThe residue is purified by chromatography on a silica column (elution solvent: 5% methanol in dichloromethane)

Sources & evidence

ORD record
ord-e1252168af824cd9993f59b6c227dee4
Source dataset
uspto-grants-2000_05
Patent number
US06060508

Reaction notes

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