Toluene → Benzopyran

HRID 2226634Notes

Reaction equation

HRID 2226634 reaction equation
CC(C)=[CH:3][CH:4]=[O:5].[Cl-].[NH4+].[C:9]1([CH3:15])[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1>[O-]CC.[O-]CC.[O-]CC.[O-]CC.[Ti+4]>[O:5]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH:15]=[CH:3][CH2:4]1

Participants

5

Reactant 3

HCID 1140Toluene2×HCID 25517Ammonium ChlorideHCID 610203-Methyl-2-butenal

Product 1

HCID 9211Benzopyran

Reagents, catalysts & solvents 1

HCID 76524Titanium tetraethoxideCatalyst

Procedure

In 100 ml of toluene was dissolved 10 g (0.0328 mole) of a compound represented by the following formula: ##STR253## and 18.71 g (0.00820 mole) of titanium tetraethoxide was added to the solution at room temperature. Ethanol was removed by azeotropic distillation. Then, toluene was added to the residue to form 500 ml of a reaction liquid. Then, a solution of 4.14 g (0.0492 mole) of 3-methyl-2-butenal in 300 m of toluene was added to the reaction liquid and the mixture was refluxed for 8 hours. After the reaction, a saturated aqueous solution of ammonium chloride was added to the reaction liquid and the mixture was extracted with ether. The solvent was removed under reduced pressure and the remaining product was purified by the chromatography on silica gel to obtain 6 g of a chromene compound represented by the following formula: ##STR254##

Workup

  1. customEthanol was removed by azeotropic distillation
  2. additionThen, toluene was added to the residue
  3. customto form
  4. custom500 ml of a reaction liquid
  5. temperaturethe mixture was refluxed for 8 hours
  6. customAfter the reaction
  7. extractionthe mixture was extracted with ether
  8. customThe solvent was removed under reduced pressure
  9. customthe remaining product was purified by the chromatography on silica gel

Sources & evidence

ORD record
ord-50e927b057eb480b8fddb1feb82e54e2
Source dataset
uspto-grants-1994_09
Patent number
US05349065

Reaction notes

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