Synthesis and Herbicidal Activity of Novel Pyrimidinyl Derivatives Containing an α-Amino Phosphonate Moiety

Abstract

In order to find novel pyrimidinyl carboxylic acid analogs with high activity and low toxicity, a series of novel pyrimidinyl derivatives containing an α-amino phosphonate moiety 5 was synthesized by the condensation of 4-(4,6-dimethoxypyrimidin-2-yloxy)phenoxyacetic 3a or propionic acids 3b with dialkyl α-amino substitutedbenzyl phosphonates 4. Their structures were characterized by spectroscopic data (IR, ¹H NMR, ³¹P NMR, MS) and elemental analyses. The results of preliminary herbicidal activities (in vitro) showed that most of these compounds exhibited higher herbicidal activities against dicotyledonous weeds (Brassica campestris L) than monocotyledonous weeds (Echinochloa crus-galli). Further bioassays (in vivo) indicated that some of compounds 5 possessed selective herbicidal activity against amaranth pigweed (A. retroflexus) in post-emergence treatment.

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Keywords:

• α-Amino phosphonate
• aryloxyphenoxy carboxylic acid
• herbicidal activity
• pyrimidinylcarboxylic acid

Acknowledgments

This work was supported by the National Natural Science Foundation of China (20872046) and the Natural Science Foundation of Hubei Province (2008CDB086).