Thioacetalization of variety of heterocyclic, aromatic and aliphatic carbonyl containing compounds (1mmol) by 1,2-ethanedithiol (1mmol) was carried out by silica sulfuric acid (SSA) as an efficient heterogeneous catalyst in mild and solvent-free conditions at 60 °C. Thioacetals were produced and isolated in 90-98% yield after extractive workup and chromatography on silica gel. The competitive protection reaction between aldehyde and ketone with 1,2-ethanedithiol afforded the protected derivatives of benzaldehyde and acetophenone in 92% and 8% yields, respectively. The method is convenient with ease of operation, short reaction times and high yields.
