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

Participants

Reaction Steps

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)

Provenance & Evidence