Abstract
A series of the O-pyrimidinylsalicylic acids were synthesized and their herbicidal activity was evaluated. Investigation of substituents on the benzene ring revealed that the 6-halogeno derivatives exhibited high herbicidal activity, but with severe phytotoxicity to some crops. The replacement of a bridge atom between two rings with other atoms or groups was performed. The S-pyrimidinylthiosalicylic acids replaced by sulfur improved the safety to cotton plants dramatically reducing herbicidal activity against broadleaf weeds to some extent. Out of the S-pyrimidinylthiosalicylic acids, 6-chloro-2-(4, 6-dimethoxypyrimidin-2-yl)thiosalicylic acid was selected as a quite promising compound for the development of a possible cotton field herbicide.
