Benzophenone → 1,1-diphenyl-2-pyridin-4-ylethanol

HRID 1249579Notes

Reaction equation

HRID 1249579 reaction equation
[N:1]1[CH:6]=[CH:5][C:4]([CH3:7])=[CH:3][CH:2]=1.C1([Li])C=CC=CC=1.C1CCCCC1.[C:21]([C:29]1[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=1)(=[O:28])[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>O1CCCC1.CCOCC>[C:29]1([C:21]([C:22]2[CH:23]=[CH:24][CH:25]=[CH:26][CH:27]=2)([OH:28])[CH2:7][C:4]2[CH:5]=[CH:6][N:1]=[CH:2][CH:3]=2)[CH:30]=[CH:31][CH:32]=[CH:33][CH:34]=1

Participants

7

Reactant 4

HCID 3102Benzophenone2×HCID 79634-MethylpyridineHCID 8078CyclohexaneHCID 178506676HCID 178506676, compound

Product 1

HCID 3031941,1-diphenyl-2-pyridin-4-ylethanolYield 94%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

A flame-dried, 12-L flask equipped with a mechanical stirrer, thermometer, and dropping funnel was charged under argon with 252.5 g of 4-picoline and 2.50 L of tetrahydrofuran. The solution was cooled in an ice bath to below 20° and maintained at 15°-20° during the addition over 15 minutes, of 1.315 L of 1.85M phenyllithium in 70:30 cyclohexane:ether solution. The mixture was stirred at 15°-20° for 30 minutes and then cooled to -5°-0° in an acetone-ice bath. The temperature was maintained in this range during the rapid addition of a solution of 494.2 g of benzophenone in 1.50 L tetrahydrofuran. A bright blue color persisted after the addition of just a little of the benzophenone solution. The cooling bath was removed and the mixture was stirred at ambient temperature for 3 hours. To the flask was added 1.0 L of deionized water and 2.0 L of tetrahydrofuran. The mixture was warm gently on a steam bath to dissolve all the solids. The aqueous phase was separated and extracted with 2.0 L of tetrahydrofuran. The combined organic solutions were dried over sodium sulfate and stripped of solvent on a rotary evaporator at 45°. The resulting solid was triturated at reflux with 1.60 L of hexanes. The suspension was stored at 4° overnight and filtered. The solids were washed with a total of 1.0 L of boiling point 35°-60° petroleum ether and dried in a forced air oven at 75° to give 699.6 g (94% yield) of alpha,alpha-diphenyl-4-pyridineethanol as a pale-yellow solid, mp 154°-155°.

Workup

  1. temperatureThe solution was cooled in an ice bath to below 20°
  2. temperaturecooled to -5°-0° in an acetone-ice bath
  3. customThe cooling bath was removed
  4. stirringthe mixture was stirred at ambient temperature for 3 hours
  5. additionTo the flask was added 1.0 L of deionized water and 2.0 L of tetrahydrofuran
  6. temperatureThe mixture was warm gently on a steam bath
  7. dissolutionto dissolve all the solids
  8. customThe aqueous phase was separated
  9. extractionextracted with 2.0 L of tetrahydrofuran
  10. dry with materialThe combined organic solutions were dried over sodium sulfate
  11. customstripped of solvent on a rotary evaporator at 45°
  12. customThe resulting solid was triturated
  13. temperatureat reflux with 1.60 L of hexanes
  14. waitThe suspension was stored at 4° overnight
  15. filtrationfiltered
  16. washThe solids were washed with a total of 1.0 L of boiling point 35°-60° petroleum ether
  17. customdried in a forced air oven at 75°

Sources & evidence

ORD record
ord-53b28824744a43518f5874581c45786b
Source dataset
uspto-grants-1986_12
Patent number
US04632925

Reaction notes

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