p-Toluenesulfonic acid → 2-(3,5-Difluorophenyl)-5-propyl-1,3-dioxane

Participants

Reaction Steps

2-Propyl-1,3-propanediol (83.2 g; 704 mmol) and 3,5-difluorobenzaldehyde (100 g; 704 mmol) were dissolved in toluene (1 liter), and p-toluenesulfonic acid (hereinafter referred to as PTS; 5 g) was added. The mixture was refluxed for 3 hours while being dehydrated with a Dean-Stark's device. The resultant reaction mixture was washed sequentially with saturated sodium bicarbonate solution and saturated brine and dried over magnesium sulfate. Subsequently, the solvent was evaporated. The residue was recrystallized twice from heptane, to thereby obtain 82.0 g (338 mmol) of 5-propyl-2-(3,5-difluorophenyl)-1,3-dioxane. The yield of the compound from 3,5-difluorobenzaldehyde was 48.0%.

Provenance & Evidence