Synthetic Studies on 2H-Thiopyran Compounds: A Reinvestigation of the Reaction Between Benzaldehydes and Sodium Sulfide

Abstract

An investigation regarding the synthesis of 2H-thiopyran compounds from substituted benzaldehydes with sodium sulfide (Na₂S·10H₂O) in aqueous ethanol was carried out. The structural elucidation of the products was performed by spectroscopic methods and in one example as X-ray crystallographic analysis. A plausible mechanistic pathway is also proposed that is entirely different from an earlier report.

Keywords:

• Benzaldehyde
• microwave irradiation
• NMR
• sodium sulfide
• 2H-thiopyran
• X-ray crystallography

The authors thank the Indian Council for Cultural Relation (ICCR) for financial assistance to P. K. Biswas.

The present affiliation for P.K.B. is BCSIR Laboratory, Dhanmondi, Dhaka, Bangladesh.

The present affiliation for D.B. is Department of Chemistry, The University of Texas–Pan American, Edinburg, Texas, USA.