SYNTHESIS AND STUDIES WITH 2-C14-LABELED BROMACIL AND TERBACIL

The half life of 2-C14-labeled bromacil and terbacil in soil was determined to be approximately 5 to 6 months when 4 pounds of active ingredient per acre was applied to the surface of Butlertown silt loam. About 90% of the residual activity recovered from the soil in these field tests was intact bromacil and terbacil. In laboratory studies, 25 to 32% of the total applied C14-activity was lost as C14O2 from soil in 6- to 9-week exposures. In orange seedlings, bromacil was the principal residue in the plants. 5-Bromo-3-sec-butyl-6-hydroxy methyl uracil and a few related minor metabolites have been identified by thin-layer chromatography as metabolites of bromacil in both soil and orange plants. No 5-bromouracil or 5-chlorouracil was detected as a metabolite of bromacil or terbacil, respectively, in these soil and plant studies. © 1969, American Chemical Society. All rights reserved.