Abstract: Thirty-one title compounds, including Ia-1 to Ia-16 and Ib-1 to Ib-15, were synthesized through nucleophilic substitution of bispyribac with various brominated carboxylic acid esters in the presence of potassium carbonate. Their structures were confirmed using ¹H NMR, ¹³C NMR, and HRMS. Preliminary herbicidal activity results indicated that these compounds exhibited similar but varying degrees of inhibitory activity on barnyard grass at dosages of 100 and 10 mg/L. Compound Ib-13 showed the highest activity, with inhibition rates of fresh weight on barnyard grass at 92.98% and 58.40%, respectively, although lower than the control herbicide pyribenzoxim (100.00% and 94.10%). The photolytic behavior of Ib-11 revealed that it is highly stable under light irradiation, suggesting these compounds are not easily degraded to bispyribac, which could explain why they display lower activity than bispyribac oxime esters and phenolic esters.