Simple Procedure for the Synthesis of 5,7-Diarylpyrido[2,3-d]pyrimidine Derivatives catalyzed by KF-Alumina

Abstract

A simple KF/Al₂O₃-catalyzed reaction of 1,3-diaryl-2-propen-1-one and 2,6-diamino-4-hydroxylpyrimidine in ethyl alcohol gave aromatized 5,7-diarylpyrido[2,3-d]pyrimidine derivative by air oxidation. On the other hand, the unaromatized intermediate products were isolated under dry nitrogen successfully. A possible reaction mechanism with two pathways to lose water was proposed based on the further experimental results; one of them was confirmed by ¹H NMR spectra of isolated intermediate product.

Keywords:

• Air oxidation
• KF-Al₂O₃
• pyrido[2,3-d]pyrimidine
• Synthesis

ACKNOWLEDGMENTS

We are grateful to the Natural Science Foundation (06AXL010) of Xuzhou Normal University for financial support.

Notes

^a Reaction condition: 10 mL solvent, 2 mmol 1, 2 mmol 2.

^b Isolated yields.

^a Reaction condition: 10 mL EtOH, 2 mmol 1, 2 mmol 2, 100 mg KF-Al₂O₃, 80°C.

^b Isolated yields.

^a Reaction condition: 10 mL EtOH, 2 mmol 1, 2 mmol 2, 100 mg KF-Al₂O₃, 80 °C.

^b Isolated yields.