Synthesis of phenoxyacetic acid and related compounds as plant growth regulators

Abstract

Forty-five substituted phenoxyacetic acids and their analoogues, thirteen derivatives (amides, esters, sodium and calcium salts) and eleven N-(2,4-dichlorophenxyacetyl)-amino acids were synthesized. These well-characterized compounds were subjected to biological activity test to comprehend the structure-activity relationship (SAR) between their structures and weed growth inhibition against Mimosa pigra Linn. And root growth promotion test of Coleus are atropurpurreus Benth. The inhibition activity over 85% was observed from six cpmpnds: 4-chloro,4-methoxyphenoxyacetic acid, 2,4-dichlorophenoxyacetamide, sodium 4-cholorophenoxyaetate, N-(2,4-dichlorophenoxyacetyl)-glycine methyl ester and N-(2,4-dichlorophenoxyaetyl)-L-glutamic acid dimethyl ester. These six compounds displayed the activity comparable with two commercial herbicides. For root growth promotion test, five compounds,namely3-fluorophenoxyaceticacid,N-phenyl-,N-cyclohexyl-2,4-dichlorophenoxyacetamide,N-(2,4-dichlorophenoxyacetyl)-DL-alanine and N-(2,4-dichlorphenoxyacetyl)-glycine methyl ester revealed more than 70% promotion and higher activity than two commercially available root promoting substances.