An Efficient Method for Thioacetalization of Carbonyl Compounds in the Presence of a Catalytic Amount of Benzyltriphenylphosphonium Tribromide Under Solvent-Free Conditions

Abstract

A variety of carbonyl compounds have been successfully converted to the corresponding thioacetal derivatives in good to excellent yields on the reaction of carbonyl compounds with 1,2-ethanedithiole, 1,3-propanedithiol, and ethanethiol in the presence of catalytic amount of benzyltriphenylphosphonium tribromide under solvent-free conditions. Some of the major advantages of this method are mild reaction conditions, high efficiency, and compatibility with other reported methods. In addition, no bromination occurs at the double bond, or α to the keto position, or even in the aromatic ring under these experimental conditions.

Keywords:

• Aldehydes
• solvent free
• thioacetalization
• tribromide

Acknowledgments

We gratefully acknowledge the funding support received for this project from the Isfahan University of Technology (IUT) I. R. Iran (Abdol R. Hajipour); and Grants GM 033138, MH 065503, NS 033650 (Arnold E. Ruoho) from the National Institutes of Health, USA. Further financial support from Center of Excellency in Chemistry Research (IUT) is gratefully acknowledged.

Notes

^a Confirmed by TLC, GC, IR, ¹H, ¹³C NMR, and CHN analysis.

^b Yield of isolated pure product after purification.

^a Confirmed by TLC, GC, IR, ¹H, ¹³C NMR, and CHN analysis.

^b Yield of isolated pure product after purification.