Trifluoroacetic acid → 2-Cyclohexyl-8-methyl-4-oxo-4H-[1]-benzopyran

HRID 1200183Notes

Reaction equation

HRID 1200183 reaction equation
[CH:1]1([C:7](=[O:19])[CH2:8][C:9]([C:11]2[CH:16]=[CH:15][CH:14]=[C:13]([CH3:17])[C:12]=2O)=[O:10])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.FC(F)(F)C(O)=O>ClCCl>[CH:1]1([C:7]2[O:19][C:12]3[C:13]([CH3:17])=[CH:14][CH:15]=[CH:16][C:11]=3[C:9](=[O:10])[CH:8]=2)[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6]1

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 146504291-Cyclohexyl-3-(2-hydroxy-3-methylphenyl)-1,3-propanedione

Product 1

HCID 146504342-Cyclohexyl-8-methyl-4-oxo-4H-[1]-benzopyran

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1-Cyclohexyl-3-(2-hydroxy-3-methylphenyl)-1,3-propanedione (5.2 g) was dissolved in dichloromethane (50 ml). Trifluoroacetic acid (4 ml) was added to the solution and the mixture was stirred at room temperature for 2 hours. The reaction mixture was concentrated under reduced pressure and then extracted with ethyl acetate. The extract was washed with water, saturated aqueous sodium bicarbonate and then water and dried (MgSO4). The solvent was distilled off under reduced pressure and the residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate (4:1)) to obtain the title compound as crystals. The crystals were recrystallized from ethyl acetate and hexane to obtain prisms (3.66 g), m.p. 108°-109° C., yield 75.6%.

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. extractionextracted with ethyl acetate
  3. washThe extract was washed with water, saturated aqueous sodium bicarbonate
  4. dry with materialwater and dried (MgSO4)
  5. distillationThe solvent was distilled off under reduced pressure
  6. customthe residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate (4:1))

Sources & evidence

ORD record
ord-f9f0d87207d7426686ccc4a3656c0ae0
Source dataset
uspto-grants-1990_02
Patent number
US04904690

Reaction notes

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