Benzophenone → HCID 520748, compound

HRID 974116Notes

Reaction equation

HRID 974116 reaction equation
COC1C=CC=C(OC)C=1.C(Cl)(=O)C1C=CC=CC=1.[Cl-].[Al+3].[Cl-].[Cl-].C(C1C=CC=CC=1)(=O)C1C=CC=CC=1.C(O)C#C.C1C2C(=CC=CC=2)C=CC=1O.[C:53]1([C:59]2([C:73]3[CH:78]=[CH:77][C:76]([O:79][CH3:80])=[CH:75][C:74]=3[O:81][CH3:82])[O:64]C3C=CC4C(C=3C=C2)=CC=CC=4)[CH:58]=[CH:57][CH:56]=[CH:55][CH:54]=1>C(=S)=S.C1(C)C=CC=CC=1>[CH3:82][O:81][C:74]1[CH:75]=[C:76]([O:79][CH3:80])[CH:77]=[CH:78][C:73]=1[C:59]([C:53]1[CH:58]=[CH:57][CH:56]=[CH:55][CH:54]=1)=[O:64]

Participants

10

Reactant 7

HCID 3102BenzophenoneHCID 7412Benzoyl chlorideHCID 7859Propargyl alcohol2×HCID 86632-NaphtholHCID 90251,3-DimethoxybenzeneHCID 6451240Aluminum(III) ChlorideHCID 21466763HCID 21466763, compound

Product 1

HCID 520748HCID 520748, compound

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent2×HCID 6348Carbon DisulfideSolvent

Procedure

2,4-dimethoxybenzophenone was prepared by the Friedel-Crafts reaction of 1,3-dimethoxybenzene with benzoyl chloride in carbon disulfide using aluminum chloride as the catalyst 11.4 grams (0.05 mole) of the resulting benzophenone was converted to the propargyl alcohol using the conditions described in Example 1, Step 2. The crude propargyl alcohol was taken up in 150 milliliters of toluene. 3 grams (0.02 mole) of 2-naphthol and 30 grams of anhydrous acidic alumina were added to the toluene solution. The resulting slurry was refluxed for 3 hours, cooled and filtered. The alumina was separated from the reaction mixture and washed with toluene until no more photochromic was extracted therefrom. The solvent solutions were combined and the toluene solvent removed on a rotary evaporator. The residue was chromatographed on silica using a 4:1 mixture of hexane and ethyl acetate as elutant. The photochromic fractions were combined and re-chromatographed using a 3:7 mixture of hexane and chloroform as elutant. The photochromic product readily crystallized from hexane. 2.6 grams of crystallized product having a melting range of 132-134° C. were obtained. NMR analysis of the product confirmed it to be 3-phenyl-3-(2,4-dimethoxyphenyl)-3H-naphtho[2,1-b]pyran.

Workup

  1. temperatureThe resulting slurry was refluxed for 3 hours
  2. temperaturecooled
  3. filtrationfiltered
  4. customThe alumina was separated from the reaction mixture
  5. washwashed with toluene until no more
  6. extractionphotochromic was extracted
  7. customthe toluene solvent removed on a rotary evaporator
  8. customThe residue was chromatographed on silica using
  9. additiona 4:1 mixture of hexane and ethyl acetate as elutant
  10. customre-chromatographed
  11. additiona 3:7 mixture of hexane and chloroform as elutant
  12. customThe photochromic product readily crystallized from hexane
  13. customwere obtained

Sources & evidence

ORD record
ord-ec76e2c87319458c8f96d6903dc91c41
Source dataset
uspto-grants-1991_11
Patent number
US05066818

Reaction notes

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