p-Toluenesulfonic acid → Ethyl ({[2-(4-chlorophenyl)-5,5-dimethyl-1,3-dioxan-2-yl]methyl}thio)acetate

HRID 254098Notes

Reaction equation

HRID 254098 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=[O:17])[CH2:9][S:10][CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13])=[CH:4][CH:3]=1.[CH3:18][C:19]([CH3:24])([CH2:22]O)[CH2:20][OH:21].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2([CH2:9][S:10][CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13])[O:21][CH2:20][C:19]([CH3:24])([CH3:22])[CH2:18][O:17]2)=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 31344Neopentyl glycolHCID 14923350Ethyl {[2-(4-chlorophenyl)-2-oxoethyl]thio}acetate

Product 1

HCID 86619094Ethyl ({[2-(4-chlorophenyl)-5,5-dimethyl-1,3-dioxan-2-yl]methyl}thio)acetateYield 31.3%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Ethyl {[2-(4-chlorophenyl)-2-oxoethyl]thio}acetate (8.15 g, 29.9 mmol) was dissolved in toluene (165 ml). 2,2-Dimethyl-1,3-propanediol (24.8 g, 238 mmol) and p-toluene sulfonic acid (300 mg) were added. The mixture was stirred at reflux in a Dean-Stark apparatus for 2.5 h and concentrated under reduced pressure. The crude product was dissolved in CH2Cl2. The mixture was washed with H2O (3×), brine, dried (Na2SO4) and concentrated under reduced pressure. The residue was purified by flash-chromatography (Hexane:EtOAc 9:1) to give 3.36 g (31%) of the title compound as an yellow oil. MS (CI) M/z: 381.0 (M++Na, 100), 382.0 (15), 383.0 (30), 384 (5)

Workup

  1. temperatureat reflux in a Dean-Stark apparatus for 2.5 h
  2. concentrationconcentrated under reduced pressure
  3. dissolutionThe crude product was dissolved in CH2Cl2
  4. washThe mixture was washed with H2O (3×), brine
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by flash-chromatography (Hexane:EtOAc 9:1)

Sources & evidence

ORD record
ord-a6194210e37741e7993b61983e8f0851
Source dataset
uspto-grants-2011_01
Patent number
US07871998B2

Reaction notes

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