Silica-Gel–Catalyzed Conversion of Stabilized Phosphorus Ylides to Benzo[e][1,3]Thiazocin Derivatives

Abstract

The reaction between triphenylphosphine, dialkylacetylenedicarboxylates, and N-benzoyl thiourea derivatives leads to intermediates such as vinyltriphenylphosphonium salts, which undergo Michael addition to produce the highly functionalized phosphorus ylides containing alkyl groups in excellent yields. Using silica gel as a catalyst, the conversion of the stabilized phosphorus ylides to benzo[e][1,3]thiazocin derivatives in solvent free conditions at 90°C in fairly high yields is achieved.

Keywords:

• Benzo[e][1,3]thiazocin derivatives
• benzoyl isothiocyanate
• N-benzoyl thiourea derivatives
• dialkylacetylenedicarboxylates
• silica gel

Acknowledgments

This work was supported by the Urmia Islamic Azad University Research Council.