Design, synthesis and bioactivity evaluation of novel benzophenone hydrazone derivatives.

BACKGROUND: Benzophenone hydrazone derivatives are among the most important classes of synthetic insecticides. In an effort to discover new molecules with good insecticidal/acaricidal activities, a series of novel benzophenone hydrazone N-acylated thiourea and urea derivatives was synthesized and bioassayed.
RESULTS: All of these compounds exhibited excellent bioactivities against T. cinnabarinus and B. brassicae, especially towards T. cinnabarinus with LC50 values ranging from 0.305 to 2.036 mmol L(-1). Moreover, the acaricidal activities against T. cinnabarinus of compounds 8a-i, 12b-f and 12h were 2.5-5.5-fold that of parent molecule 3 based on the LC50 value.
CONCLUSION: Based on the observed bioactivities, the structure-activity relationship of these analogs was also discussed. Structure-activity relationships provided information that could direct further investigation on structure modification. Our studies indicated that benzophenone hydrazone N-acylated thiourea and urea derivatives could be used as potential lead compounds for developing novel acaricides and insecticides.