Synthesis and Biological Activity of Triclopyr Derivatives Containing the Pyridine Group

Background: Triclopyr(Dow-503), whose commercial name was green grass, was an internal absorption and selective novel herbicide, developed by Dow agricultural sciences using the basic structure of 2,4-D. Triclopyr was suitable for preventing broadleaf weeds for removing shrubs, maintaining fireproof lines, raising pine trees and forest areas. Moreover, it could be used in paddy fields to prevent some broad-leaved weeds at the dose of 150-500g/hm. Methods: Two novel Triclopyr derivatives were synthesized based on the structure of commerical herbicide Triclopyr. Their structures were confirmed by 1H NMR melting point and elemental analysis. The preliminary bioassay were also evaluated. Results: The preliminary bioassay results showed that the title compounds had some herbicidal activities at the dosage of 150 g/hm2.The compound 1 and 2 show the 100% inhibition against three kinds of test weeds. Further test revealed that compound 2 showed the 100% inhibition against the Amaranthus. The safety test for crop revealed that the compound 2 was safe for paddy at the dosage of 150 g/hm2. Conclusion: The two compounds can be used as the leading compounds with certain optimized value.