Sodium Salts of Alkylphosphinic Acids IIIH

2 Sodium Salts of Alkylphosphinic Acids IIIH 4.2.1 Introduction 

As stated in Chap. 7, salts of l-(substimted phenoxyacetoxy)alkylphosphonate showed higher inhibitory activity against plant PDHc El than their corresponding phosphonic ester did, because these salts were more analogous to pyruvate which acted as the substrate of PDHc El. 

In the niH series, further modification was focused on substituent and Y . In this section, we introduce the synthesis, herbicidal activity, and stracture-activity relationships of IIIH. As expected, IIIH possessed higher inhibitory activity against the growth of plant than their corresponding phosphinates HIG. 

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Comparing sodium salts of alkylphosphinic acids IIIH with their corresponding phosphinates HIG, it was found that inhibitory activity against the growth of plant could be greatly enhanced when MeO attached to phosphorus in phosphinates HIG was replaced by NaO. The results of study on IIIH are described in Chap. 4. 

Scheme 1.30 Design of sodium salts of alkylphosphinic acids IIIH by modification of IIIA-IIIG...

As seen from Table 4.22, all of sodium salts of alkylphosphinic acids IIIH showed moderate to good herbicidal activity against the root of barnyard grass and rape at 100 and 10 mg/L. Especially, IIIH-I (Yn=3-CF3, R =Ph), IIIH-2 ( =2,4-... 

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