Benzophenone → (2,6-Difluorophenyl)(4-methoxyphenyl)methanone

HRID 974117Notes

Reaction equation

HRID 974117 reaction equation
FC1C=CC=C(F)C=1C(Cl)=O.C1(OC)C=CC=CC=1.C(C1C=CC=CC=1)(=O)C1C=CC=CC=1.C(O)C#C.C1C=CC2C(=CC=CC=2O)C=1.[OH-].[Na+].[F:51][C:52]1[CH:57]=[CH:56][CH:55]=[C:54]([F:58])[C:53]=1[C:59]1([C:73]2[CH:78]=[CH:77][C:76]([O:79][CH3:80])=[CH:75][CH:74]=2)[O:64]C2C=CC3C(C=2C=C1)=CC=CC=3>C(=S)=S.[Cl-].[Al+3].[Cl-].[Cl-].C1C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>[F:51][C:52]1[CH:57]=[CH:56][CH:55]=[C:54]([F:58])[C:53]=1[C:59]([C:73]1[CH:74]=[CH:75][C:76]([O:79][CH3:80])=[CH:77][CH:78]=1)=[O:64]

Participants

12

Reactant 7

HCID 3102BenzophenoneHCID 70051-NaphtholHCID 7519AnisoleHCID 7859Propargyl alcohol2×HCID 14798Sodium HydroxideHCID 874382,6-Difluorobenzoyl chlorideHCID 214667653-(2,6-Difluorophenyl)-3-(4-methoxyphenyl)-3H-naphtho[2,1-b]pyran

Product 1

HCID 19987799(2,6-Difluorophenyl)(4-methoxyphenyl)methanone

Reagents, catalysts & solvents 4

HCID 6101p-Toluenesulfonic acidCatalystHCID 6451240Aluminum(III) ChlorideCatalystHCID 241BenzeneSolvent2×HCID 6348Carbon DisulfideSolvent

Procedure

2,6-difluoro-4'-methoxybenzophenone was prepared by Friedel-Crafts reaction of 2,6-difluorobenzoyl chloride with anisole in carbon disulfide using aluminum chloride as catalyst. 4.8 grams (0.02 mole) of the benzophenone was converted to the propargyl alcohol using the conditions described in Example 1, Step 2. The crude propargyl alcohol was taken up in 200 milliliters of benzene and 3.0 grams (0.02 mole) of naphthol and 0.1 grams of p-toluene sulfonic acid catalyst was added to the benzene solution. After stirring for 1 hour, the reaction mixture was poured into an equal volume of 5 percent aqueous sodium hydroxide. The organic layer was separated and the benzene solvent removed on a rotary evaporator. The residue was chromatographed on silica using a 4:1 mixture of hexane:ethyl acetate as elutant. The photochromic fractions were collected and crystallized from n-propanol. 1.2 grams of product having a melting range of 122-124° C. was obtained. NMR analysis confirmed the product to be 3(2,6-difluorophenyl)-3(4-methoxyphenyl)-3H- naphtho[ 2,1-b]pyran.

Workup

  1. customThe organic layer was separated
  2. customthe benzene solvent removed on a rotary evaporator
  3. customThe residue was chromatographed on silica using
  4. additiona 4:1 mixture of hexane
  5. customThe photochromic fractions were collected
  6. customcrystallized from n-propanol
  7. customwas obtained

Sources & evidence

ORD record
ord-e7725307cd854309a1623013337b2a60
Source dataset
uspto-grants-1991_11
Patent number
US05066818

Reaction notes

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