Water → 8-Bromo-5-methoxy-3-chromanol

HRID 1464693Notes

Reaction equation

HRID 1464693 reaction equation
[OH2:1].[CH2:2]([O:5][C:6]1[CH:7]=[C:8]([O:13][CH3:14])[CH:9]=[CH:10][C:11]=1[Br:12])[CH:3]=[CH2:4]>OS(O)(=O)=O>[Br:12][C:11]1[CH:10]=[CH:9][C:8]([O:13][CH3:14])=[C:7]2[C:6]=1[O:5][CH2:2][CH:3]([OH:1])[CH2:4]2

Participants

4

Reactant 2

HCID 962Water3×HCID 147034223-Allyloxy-4-bromoanisol

Product 1

HCID 147034238-Bromo-5-methoxy-3-chromanolYield 24%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent2×

Conditions

Temperature
60 °C

Procedure

To a mixture of H2SO4 (6.9 ml) and water (6.1 ml) at room temperature was added Tl2O3 (2.38 g, 5.22 mmol). The mixture was stirred for 30 min and water (37 ml) was added, thereafter the temperature was raised to 60° C. and 3-allyloxy-4-bromoanisol (2.16 g, 8.89 mmol) was added. The mixture was stirred at 60° C. for 4.5 hours. Another portion of Tl2O3 (1.0 g, 2.19 mmol) stirred for 30 min at 20° C. in H2SO4 (2.6 ml) and H2O (3 ml) was added and the reaction mixture was stirred for another 17 hours at 60° C. After cooling the mixture was extracted with chloroform. The organic layer was washed with water, dried (MgSO4) and evaporated. After chromatography (SlO2) with ether as eluant, 552 mg (24%) of 8-bromo-5-methoxy-3-chromanol was isolated. An analytic sample of the product was obtained from recrystallization in light petroleum-ether, m.p. 115°-117° C.

Workup

  1. stirringThe mixture was stirred at 60° C. for 4.5 hours
  2. stirringthe reaction mixture was stirred for another 17 hours at 60° C
  3. temperatureAfter cooling the mixture
  4. extractionwas extracted with chloroform
  5. washThe organic layer was washed with water
  6. dry with materialdried (MgSO4)
  7. customevaporated

Sources & evidence

ORD record
ord-0ead132afaa24733b553be0ae748f61e
Source dataset
uspto-grants-1994_04
Patent number
US05306830

Reaction notes

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