Ethyl Bromide → 4-Fluoro-4'-hydroxy-alpha-ethyl-benzhydrol

HRID 1980398

Reaction equation

HRID 1980398 reaction equation
[CH2:1]([Li])[CH3:2].[Li].C(Br)C.[F:8][C:9]1[CH:23]=[CH:22][C:12]([C:13]([C:15]2[CH:20]=[CH:19][C:18]([OH:21])=[CH:17][CH:16]=2)=[O:14])=[CH:11][CH:10]=1.[Cl-].[NH4+]>O1CCCC1.CCOCC>[F:8][C:9]1[CH:23]=[CH:22][C:12]([C:13]([CH2:1][CH3:2])([OH:14])[C:15]2[CH:20]=[CH:19][C:18]([OH:21])=[CH:17][CH:16]=2)=[CH:11][CH:10]=1

Participants

8

Reactant 5

HCID 6332Ethyl BromideHCID 25517Ammonium ChlorideHCID 1176664-Fluoro-4'-hydroxybenzophenoneHCID 3028194LithiumHCID 178506846HCID 178506846, compound

Product 1

HCID 147273204-Fluoro-4'-hydroxy-alpha-ethyl-benzhydrol

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of ethyl lithium prepared from 2.8 g. of lithium metal and 21.8 g. of ethyl bromide in 265 ml. of dry ether a solution of 10.8 g. of 4-fluoro-4'-hydroxy-benzophenone in 50 ml. of dry tetrahydrofurane is added dropwise, with stirring in argon atmosphere, at a temperature between -40° C. and -30° C. When the addition is complete, the mixture is allowed to warm up to 0° C., and is then stirred at this temperature for further 30 minutes. The mixture is decomposed with a 20% aqueous ammonium chloride solution under cooling. The aqueous phase is extracted with ether, the ethereal phases are combined, washed to neutral with water, and dried over anhydrous magnesium sulfate. The solution is evaporated under reduced pressure, and the solid residue is crystallized from a mixture of n-hexane and ethyl acetate to yield 8.2 g. of the named product, melting at 125° to 126° C.

Workup

  1. customat a temperature between -40° C. and -30° C
  2. additionWhen the addition
  3. stirringis then stirred at this temperature for further 30 minutes
  4. temperatureunder cooling
  5. extractionThe aqueous phase is extracted with ether
  6. washwashed to neutral with water
  7. dry with materialdried over anhydrous magnesium sulfate
  8. customThe solution is evaporated under reduced pressure
  9. customthe solid residue is crystallized from a mixture of n-hexane and ethyl acetate
  10. customto yield 8.2 g

Sources & evidence

ORD record
ord-917d616c80ac4359ad0270951878f8b6
Source dataset
uspto-grants-1985_04
Patent number
US04508926

Linked notes

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