Bismuth Subnitrate Catalyzed Efficient Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐Ones: An Improved Protocol for the Biginelli Reaction

Abstract

An efficient synthesis of 3,4‐dihydropyrimidinones (DHPMs) using bismuth subnitrate as the catalyst for the first time from an aldehyde, β‐ketoester, and urea in acetonitrile is described. This new method consistently has the advantage of excellent yields (88–96%) and short reaction times (1.5–4 h) than do classical Biginelli reaction conditions.

Keywords:

• Biginelli reaction
• Bismuth subnitrate
• Dihydropyrimidinones
• One‐pot condensation

Acknowledgment

The authors are thankful to AICTE, New Delhi, for financial assistance and to the director, IICT, Hyderabad for ¹H‐NMR and mass spectral analysis.