Reaction #6482

Reaction equation

potassium hydroxide

phenylacetaldehyde

1,3-propanedithiol

boron trifluoride etherate

→

title compound

Yield 91.0%

2-Phenylmethyl-1,3-dithiane

Yield 91.0%

Solvents

methylene chloride

Conditions

Workup

1. 1
   OtherThe layers were separated
2. 2
   Extractionthe aqueous layer was extracted with methylene chloride
3. 3
   ExtractionThe combined organic extract
4. 4
   Washwas washed with 1N aqueous sodium hydroxide solution and brine
5. 5
   Dryingdried over anhydrous magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   workup.DISTILLATIONthe filtrate was distilled

Procedure

To a solution of 33.9 g (280 mmol) of phenylacetaldehyde and 35.6 g (330 mmol) of 1,3-propanedithiol in 300 mL of methylene chloride at 0° C., was added, dropwise over a period of 30 minutes, 10 mL of boron trifluoride etherate. The reaction mixture was allowed to warm to ambient temperature and stirred for 3 h at ambient temperature. The reaction mixture was made basic by the addition of 180 mL of 5% aqueous potassium hydroxide solution and the resultant mixture was stirred for 0.5 h. The layers were separated and the aqueous layer was extracted with methylene chloride. The combined organic extract was washed with 1N aqueous sodium hydroxide solution and brine, dried over anhydrous magnesium sulfate, filtered and the filtrate was distilled to afford 53.62 g (91% yield) of the title compound, b.p. 150° C. (2 mm Hg); 1H NMR (CDCl3) δ1.75-1.95 (1H, m), 2.05-2.17 (1H, m), 2.75-2.91 (4H, m), 3.03 (2H, d, J=9 Hz), 4.25 (1H, t, J=9 Hz), 7.17-7.38 (5H, m).

Source