Hydrogen Bromide → Chromanone

HRID 1282977Notes

Reaction equation

HRID 1282977 reaction equation
O=O.[C:3]([C:6]1C2C([C:13]3[CH:14]=[CH:15][CH:16]=[CH:17][C:18]=3[C:19]=1[OH:20])=CC=CC=2)(=[O:5])C.CC(C)([O-])C.[Na+].Br>C1C=CC=CC=1.C(O)(=O)C>[O:5]1[C:17]2[C:18](=[CH:13][CH:14]=[CH:15][CH:16]=2)[C:19](=[O:20])[CH2:6][CH2:3]1

Participants

7

Reactant 4

HCID 260Hydrogen BromideHCID 977OxygenHCID 640645HCID 640645, compoundHCID 23676156Sodium t-butoxide

Product 1

HCID 68110Chromanone

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 241BenzeneSolvent3×

Procedure

Oxygen derivatives analogous to those of Examples IX and X may be prepared as follows: 9-acetyl-10-hydroxyphenanthrene and the appropriate aldehyde or ketone according to Example IX in benzene are added to a solution of sodium t-butoxide in benzene and the resulting mixture refluxed for 20 hours with stirring. The reaction mixture is poured into a stirred solution of hydrobromic acid (3 parts) and acetic acid (2 parts). The benzene layer is steam distilled and the residue boiled with methanol saturated with dry hydrogen chloride 0.5-1 hour to drive the cyclization to completion. After the solvent has been removed, the chroman-4-one is isolated by chromatography and crystallization from petroleum ether solvent.

Workup

  1. custommay be prepared
  2. temperaturethe resulting mixture refluxed for 20 hours
  3. distillationdistilled
  4. customboiled with methanol saturated with dry hydrogen chloride 0.5-1 hour
  5. customAfter the solvent has been removed

Sources & evidence

ORD record
ord-3a8a2ebaf4a14fa8b372a312e391ea64
Source dataset
uspto-grants-1976_08
Patent number
US03973966

Reaction notes

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