Sulfuric Acid → I2-Ionone

HRID 2352476Notes

Reaction equation

HRID 2352476 reaction equation
S(=O)(=O)(O)O.[CH3:6][C:7]([CH3:19])=[CH:8][CH2:9][CH2:10]/[C:11](/[CH3:18])=[CH:12]/[CH:13]=[CH:14]/[C:15]([CH3:17])=[O:16]>C(O)(=O)C>[CH3:18][C:11]1[CH2:10][CH2:9][CH2:8][C:7]([CH3:19])([CH3:6])[C:12]=1/[CH:13]=[CH:14]/[C:15]([CH3:17])=[O:16]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 17570033E,5E-Pseudoionone

Product 1

HCID 638014I2-IononeYield 51%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

The cyclizing agent [35 g of conc. sulfuric acid (95%) and 15 g of glacial acetic acid] was placed in a 250 ml three-necked flask with a mechanical stirrer, a dropping funnel, and a thermometer reaching into the reaction mixture. The flask was cooled in an ice bath and the cyclizing agent was vigorously stirred while pseudoionone (10 g ) was added dropwise during 15-20 minutes; the rate of addition was adjusted so that the temperature of the reaction mixture did not exceed 10° C. After addition, the cooling bath was removed and stirring was continued at 10°-15° C. for 5-10 minutes. The reaction mixture was poured into a mixture of ice and water (200 g) and ether (100 ml) with vigorous stirring. The water layer was again extracted with ether and the combined ether extracts were washed with water, sodium carbonate solution (1%), then to neutral with water and dried over anhydrous magnesium sulphate. After the removal of ether, the residue was distilled under reduced pressure. β-Ionone (5.1 g) was obtained as a pleasant smelling light yellow colored liquid; boiling point 73° C./0.25 mm; nD25 1.5164.

Workup

  1. temperatureThe flask was cooled in an ice bath
  2. additionwas added dropwise during 15-20 minutes
  3. additionthe rate of addition
  4. customdid not exceed 10° C
  5. additionAfter addition
  6. customthe cooling bath was removed
  7. additionThe reaction mixture was poured into a mixture of ice and water (200 g) and ether (100 ml) with vigorous stirring
  8. extractionThe water layer was again extracted with ether
  9. washthe combined ether extracts were washed with water, sodium carbonate solution (1%)
  10. dry with materialto neutral with water and dried over anhydrous magnesium sulphate
  11. customAfter the removal of ether
  12. distillationthe residue was distilled under reduced pressure

Sources & evidence

ORD record
ord-92dc2389a8b94d77befd3e6c0feace38
Source dataset
uspto-grants-1989_10
Patent number
US04877607

Reaction notes

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