A New Route to 3-Phosphonylpyrazoles

Abstract

The regioselective synthesis of 3-diethoxyphosphonopyrazoles has been accomplished through the addition of aryl or alkyl hydrazines to (3-ethoxyacryloyl)phosphonic acid diethyl ester. An example of hydrolysis of the pyrazolephosphonic ester to the corresponding acid is described.

Keywords:

• Aminophosphonic acids
• cycloaddition reactions
• phosphonylpyrazoles

Acknowledgments

This research project was supported by the Faculty of Chemistry, University of Łódź.