Hydrogen Bromide → CHROMAN-8-OL

HRID 581071Notes

Reaction equation

HRID 581071 reaction equation
C[O:2][C:3]1[C:12]2[O:11][CH2:10][CH2:9][CH2:8][C:7]=2[CH:6]=[CH:5][CH:4]=1.Br.C1(O)C=CC=CC=1>C(O)(=O)C>[OH:2][C:3]1[C:12]2[O:11][CH2:10][CH2:9][CH2:8][C:7]=2[CH:6]=[CH:5][CH:4]=1

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 996PhenolHCID 13758736HCID 13758736, compound

Product 1

HCID 19033254CHROMAN-8-OL

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

The compound obtained in Step C (1 g; 6.09 mmol) is dissolved in glacial acetic acid (10.2 ml) and then hydrobromic acid (48% solution in water) (3.7 eq.; 47 mmol; 2.54 ml) is added dropwise. The phenol is fully deprotected after 5 hours' reflux. After removal of the solvent under reduced pressure, the dry residue is taken up in aqueous medium and then neutralised with a saturated sodium hydrogen carbonate solution to a pH of 8. Extraction with ethyl acetate yields an orange oil after drying and concentration. After purification of the latter over a silica column. AcOEt/PE (3:7), the oil is yellow in colour.

Workup

  1. temperature' reflux
  2. customAfter removal of the solvent under reduced pressure
  3. extractionExtraction with ethyl acetate
  4. customyields an orange oil
  5. customafter drying
  6. concentrationconcentration
  7. customAfter purification of the latter over a silica column

Sources & evidence

ORD record
ord-899b9f5b4ad14e8990d08d5c80c8e64b
Source dataset
uspto-grants-1999_07
Patent number
US05919814

Reaction notes

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