One-pot synthesis and insecticidal activity of 5-amino-1-aryl- 1H-pyrazole-4-carbonitriles

Abstract

Synthesis of 5-amino-1-aryl-1H-pyrazole-4-carbonitriles was performed by direct condensation of 29 (ethoxymethylene)malononitrile and aryl hydrazines. The resulting N,N-containing heterocycles possess 30 insecticidal properties relative to microlepidoptera species, plant phatogens. The insecticidal activity of 31 four novel synthetic N-aryl pyrazoles to Tuta absoluta larvae was assessed. Fipronil, a well-known aryl 32 pyrazole insecticide, was also tested as the positive control. A generalized linear model reported 33 significant differences in efficacy and tomato leaf consumption among the different treatments. Fipronil 34 treatment was the most effective one (100% mortality after 48 h), followed by 5-amino-1-phenyl-1H-35 pyrazole-4-carbonitrile treatment (3c) (75% mortality after 48 h) and 5-amino-1-(2,6-dichloro-4-36 (trifluoromethyl)-phenyl-1H-pyrazole-4-carbonitrile treatment (3b) (60% mortality after 48 h). These 37 compounds, with simpler structures than Fipronil, could be used as novel insecticides.