p-Toluenesulfonic acid → 4-Chloro-4'-methoxybutyrophenone

HRID 1576222Notes

Reaction equation

HRID 1576222 reaction equation
[Cl:1][CH:2](OC)[CH2:3][CH2:4][C:5]([C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)=[O:6].CC(C)(CO)[CH2:17][OH:18].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[Cl:1][CH2:2][CH2:3][CH2:4][C:5]([C:7]1[CH:8]=[CH:9][C:10]([O:18][CH3:17])=[CH:11][CH:12]=1)=[O:6]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 31344Neopentyl glycolHCID 20509887HCID 20509887, compound

Product 1

HCID 964144-Chloro-4'-methoxybutyrophenoneYield 30.9%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A solution of 45.96 g. (0.217 mole) of 4-chloro-4 -methoxybutyrophenone [prepared in (a), above], 28 g. (0.27 mole) of 2,2-dimethyl-1,3-propanediol and 0.53 g. of p-toluenesulfonic acid in 425 ml. of benzene is heated at reflux under a Dean-Stark trap for about 20 hours. The solution is allowed to cool, washed successively with aqueous sodium bicarbonate solution, water and brine and then evaporated to dryness. The residue is distilled at 174° C. at 1.5 mm. of mercury pressure and then recrystallized from petroleum ether to give 19.97 g. (30.9% yield) of 4-chloro-4'-methoxybutyrophenone, 2,2-dimethylpropylene ketal, having a melting point of 51.5 ° to 53.5° C.

Workup

  1. temperatureat reflux under a Dean-Stark trap for about 20 hours
  2. temperatureto cool
  3. washwashed successively with aqueous sodium bicarbonate solution, water and brine
  4. customevaporated to dryness
  5. distillationThe residue is distilled at 174° C. at 1.5 mm
  6. customof mercury pressure and then recrystallized from petroleum ether
  7. customto give 19.97 g

Sources & evidence

ORD record
ord-a9a104e440e1454a8783bb85f5f953d1
Source dataset
uspto-grants-1976_09
Patent number
US03979444

Reaction notes

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