Diammonium Hydrogen Phosphate: An Efficient and Versatile Catalyst for the One‐Pot Synthesis of Tetrahydrobenzo[b]pyran Derivatives in Aqueous Media

Abstract

Diammonium hydrogen phosphate was used as a mild, efficient, neutral, and cheap catalyst for the synthesis of various 4H‐benzo[b]pyran derivatives via a one‐pot, three‐component condensation of aromatic aldehydes, active methylene compounds, and dimedone in aqueous media.

Keywords:

• aqueous media
• 4H‐benzo[b]pyrans
• diammonium hydrogen phosphate
• Knoevenagel cyclocondensation

Acknowledgments

Saeed Balalaie is grateful to the Alexander von Humboldt foundation for the research fellowship and equipment donation. Partial support of this work by the K. N. Toosi University of Technology Research Council is gratefully acknowledged.