Pivaloyl chloride → 2,2-Dimethyl-1-[4-(2-methyl-1,3-dioxolan-2-yl)phenyl]propan-1-one

HRID 1973699Notes

Reaction equation

HRID 1973699 reaction equation
[Mg].[CH2:2]1[O:14][C:5]([C:7]2[CH:12]=[CH:11][C:10](Br)=[CH:9][CH:8]=2)([CH3:6])[O:4][CH2:3]1.C1OC(C2C=CC=CC=2)(CBr)OC1.[C:28](Cl)(=[O:33])[C:29]([CH3:32])([CH3:31])[CH3:30]>O1CCCC1>[CH3:6][C:5]1([C:7]2[CH:12]=[CH:11][C:10]([C:28](=[O:33])[C:29]([CH3:32])([CH3:31])[CH3:30])=[CH:9][CH:8]=2)[O:14][CH2:2][CH2:3][O:4]1

Participants

6

Reactant 4

HCID 62493Pivaloyl chlorideHCID 2915742-(Bromomethyl)-2-phenyl-1,3-dioxolaneHCID 6149202-(4-Bromophenyl)-2-methyl-1,3-dioxolaneHCID 5462224Magnesium

Product 1

HCID 545049922,2-Dimethyl-1-[4-(2-methyl-1,3-dioxolan-2-yl)phenyl]propan-1-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Conditions

Temperature
-60 °C

Procedure

To a suspension of 12.4 g (0.51 g-atoms) magnesium turnings in 190 ml tetrahydrofuran under a nitrogen atmosphere there is added 10 ml. of a solution of 103 g (0.424 mole) of 4'-bromoacetophenone ethylene ketal in 130 ml dry tetrahydrofuran. The reaction is started and the remainder of the bromoacetophenone ethylene ketal solution is added dropwise at a rate that maintains a moderate reflux. After the addition is complete, the mixture is refluxed for one hour. The resulting Grignard solution is added dropwise to a cold solution of 51.1 g (0.424 mole) pivaloyl chloride in 120 ml of dry tetrahydrofuran at a rate that maintains the temperature at 0° C. After addition the resulting solution is stirred for 1 hour at -60° C and then 1 additional hour at -10° C. The mixture is then poured onto ice and extracted with ether, the ether is washed with 2N sodium hydroxide and salt water, dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo. The resulting residue is triturated with petroleum ether to give 4'-(2-methyl-2-dioxolanyl)pivalophenone, m.p. 75°-82° C.

Workup

  1. additionthere is added 10 ml
  2. additionAfter the addition
  3. temperaturethe mixture is refluxed for one hour
  4. customat 0° C
  5. additionAfter addition the resulting solution
  6. customat -10° C
  7. additionThe mixture is then poured onto ice
  8. extractionextracted with ether
  9. washthe ether is washed with 2N sodium hydroxide and salt water
  10. dry with materialdried over anhydrous magnesium sulfate
  11. filtrationfiltered
  12. customevaporated in vacuo
  13. customThe resulting residue is triturated with petroleum ether

Sources & evidence

ORD record
ord-b520b151fa7b451395faec38a7a453d6
Source dataset
uspto-grants-1976_12
Patent number
US03998850

Reaction notes

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