Pyridine - Sulfur Trioxide Complex

Used Chemicals

• Pyridine - Sulfur Trioxide Complex (= SO₃·Py) [P0998]
• N,N-Diisopropylethylamine [D1599]
• 3,5-Dibenzyloxybenzyl Alcohol [D2651]
• DMSO [D0798]
• Dichloromethane

Procedure

To a solution of 3,5-dibenzyloxybenzyl alcohol (1.0 g, 3.1 mmol), N,N-diisopropylethylamine (2.7 mL, 15.6 mmol, 5.0 equiv), and DMSO (2.22 mL, 31 mmol, 10 equiv) in dichloromethane (10 mL) was added SO₃·Py (1.49 g, 9.4 mmol, 3.0 equiv) at 0 °C. The reaction mixture was stirred at same temperature for 1 hour and quenched with Na₂S₂O₃ aq. (20 mL) was added to the reaction mixture. The aqueous layer was extracted with dichloromethane (20 mL) and washed brine. The organic phase was concentrated under reduced pressure and the residue was purified by column chromatography (ethyl acetate:hexane = 0:1 - 1:1 on silica gel) to give 3,5-dibenzyloxybenzaldehyde as a white solid (850 mg，y. 85%).

Experimenter’s Comments

The reaction mixture was monitored by LC.
This reaction produces dimethyl sulfide, which gives off a bad smell. So that it is recommended to treat this reaction in a fume hood.

Analytical Data

3,5-dibenzyloxybenzaldehyde

¹H NMR (270 MHz, CDCl₃); δ 9.90 (s, 1H), 7.45-7.32 (m, 10H), 7.12 (d, J = 2.1 Hz, 2H), 6.87 (t, 1H, J = 2.1 Hz), 5.93 (s, 4H).

Lead Reference

• Bis(benzylamine) monomers: One-pot preparation and application in dendrimer scaffolds for removing pyrene from aqueous environments
• N. O. Monaco, C. S. Tomas, K. M. Kirrane, M. A. Balija, Beilstein J. Org. Chem. 2013, 9, 2320.

Other References

• CO₂-Catalyzed Oxidation of Benzylic and Allylic Alcohols with DMSO
• D. Rimer, B. Mandaviya, W. Schilling, A. C. Götz, T. Kühl, M. Finger, D. Das, ACS Catal. 2018, 8, 3030.

References

• E. J. Corey, K. Achiwa, J. Org. Chem. 1969, 34, 3667.
• D. S. Watt, E. J. Corey, Tetrahedron Lett. 1972, 4651.
• J. R. Parikh, W. von E. Doering, J. Am. Chem. Soc. 1967, 89, 5505.
• Y. Hamada, T. Shioiri, Chem. Pharm. Bull. 1982, 30, 1921.
• D. A. Evans, J. Bartroli, Tetrahedron Lett. 1982, 23, 807.