Twelve novel fluorobenzoylthioureas have been synthesized by the addition reactions of substituted 2-aminopyrimidine or 2-aminopyridine with fluorobenzoyl isothiocyanate ester, which was prepared by chloration and acylation of fluorocarboxylic acid. The primary factors influencing the addition reaction were discussed. Their structures were confirmed by 1H NMR, IR, GC-MS techniques and elemental analysis. The preliminary biologic tests showed that some of these target compounds had good activity as plant growth regulators at the concentration of 1 mg/L. The correlations between biological activities and molecular struc-tures of the 3-fluorobenzoylthioureas were discussed.

Key words: fluorobenzoylthiourea, synthesis, biologic activi, fluorocarboxylic acid