4,4-Dimethyl-2-phenyl-2-oxazoline → HCID 70603445, compound

HRID 46749Notes

Reaction equation

HRID 46749 reaction equation
[CH3:1][C:2]1([CH3:13])[CH2:6][O:5][C:4]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)=[N:3]1.C([Li])CCC.C(=O)=O.CC(C)=O.[Cl:26][CH2:27][Si:28]([C:31]1[CH:36]=[CH:35][C:34]([Cl:37])=[CH:33][CH:32]=1)([CH3:30])Cl>O1CCCC1.CCCCCC.CCOCC>[Cl-:26].[Cl:37][C:34]1[CH:35]=[CH:36][C:31]([Si:28]2([CH3:30])[C:12]3[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=3[C:4]3[O:5][CH2:6][C:2]([CH3:13])([CH3:1])[N+:3]=3[CH2:27]2)=[CH:32][CH:33]=1

Participants

8

Reactant 4

HCID 2892394,4-Dimethyl-2-phenyl-2-oxazolineHCID 18522661Acetone cardiceHCID 20385469HCID 20385469, compoundHCID 178418339Butyllithium

Product 1

HCID 70603445HCID 70603445, compound

Reagents, catalysts & solvents 3

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Conditions

Temperature
-35 °C

Procedure

To 44.2 g (252 m mol) of 4,4-dimethyl-4,5-dihydro-2-phenyl oxazole in 570 ml of absolute tetrahydrofuran under nitrogen is added at -50° C. to -45° C. with stirring 173 ml (277 m mole) of 1.6 N n-butyl lithium in hexane. Stirring is continued at that temperature for 1.5 hours except for a brief period at the end thereof to allow for warming to -35° C. The resulting mixture containing a yellow precipitate is re-cooled with dry ice-acetone and 61 g (255 m mol) of chloromethyl-p-chlorophenyl methyl chloro silane is added maintaining the temperature at between -78° C. and -55° C. The contents are allowed to warm to room temperature over a period of 3 hours and the resulting homogeneous solution is maintained at room temperature for an additional 20 hours. Addition of 1.2 ml of ether-ligroine (1:1) precipitates a semi-solid. The supernatent liquid is decanted and the residue is combined with 300 ml of methylene chloride and stirred briefly. The light slurry is filtered to remove lithium chloride and the mother liquor is concentrated in vacuo to 67.9 g of pink foam. Most of the foam is dissolved in cold water, sodium chloride solution (ca. 30%) is added, the aqueous phase is extracted with ethyl acetate to remove some impurities, and the remainder is extracted with chloroform. The chloroform phase is dried with sodium sulfate and evaporated. Addition of acetone and ether yields crystalline product having a melting point of 119°-121° C. Recrystallization from acetone-ethyl acetate (Ca. 1:1) provides product melting at 118°-120° C.

Workup

  1. additionThe resulting mixture containing a yellow precipitate
  2. additionis added
  3. temperaturemaintaining the temperature at between -78° C. and -55° C
  4. temperatureto warm to room temperature over a period of 3 hours
  5. temperaturethe resulting homogeneous solution is maintained at room temperature for an additional 20 hours
  6. customprecipitates a semi-solid
  7. customThe supernatent liquid is decanted
  8. stirringstirred briefly
  9. filtrationThe light slurry is filtered
  10. customto remove lithium chloride
  11. concentrationthe mother liquor is concentrated in vacuo to 67.9 g of pink foam
  12. dissolutionMost of the foam is dissolved in cold water
  13. additionsodium chloride solution (ca. 30%) is added
  14. extractionthe aqueous phase is extracted with ethyl acetate
  15. customto remove some impurities
  16. extractionthe remainder is extracted with chloroform
  17. dry with materialThe chloroform phase is dried with sodium sulfate
  18. customevaporated
  19. additionAddition of acetone and ether
  20. customyields crystalline product
  21. customRecrystallization from acetone-ethyl acetate (Ca. 1:1)

Sources & evidence

ORD record
ord-73ee06b9c3bb4138bf42c0621b327c2c
Source dataset
uspto-grants-1979_11
Patent number
US04175091

Reaction notes

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