Exploration of Some Heterocyclic Compounds Containing Trifluoromethylpyridine Scaffold as Insecticides Toward Aphis gossypii Insects.

Five types of heterocyclic compounds containing trifloromethylpyridine scaffold namely; 3-cyano-2-(N-phenyl)carbamoylmethylthio-6-(thiophen-2-yl)-4-trifluoromethyl-pyridine (6a), thieno[2,3-b]pyridines 3-5 and 7a-c, pyrido[3',2':4,5]thieno[3,2-d] pyrimidines 8-13 and 15a-c, pyrido[3',2':4,5]thieno[3,2-d][1,2,3]triazines 16a,b, and 9-(thiophen-2-yl)-7-(trifluoromethyl) pyrido [3',2':4,5]thieno[2,3-e][1,2,4]triazolo[1,5-c]pyrimidine (14) were synthesized in excellent yields and very pure state. The structures of these compounds were confirmed by elemental and spectral analyses. Most of the synthesized compounds were evaluated as insecticidal agents toward Aphis gossypii insects and promising results obtained. Among all tested compounds, only 6, 7a, 7c and 15c being the most potent compounds against nymphs and adults of Aphis gossypii and their activities are nearly to that of acetamiprid as a reference. The effect of 6a compounds 7a, 7c and 15c on the Aphis digestive system from histological point of view was also included.

Green synthesis and bioefficacy screening of new insect growth regulators as eco-friendly insecticides against the cotton mealybug Phenacoccus solenopsis.

Overcoming or reducing the majority of difficulties caused by the use of common pesticides requires the use of developed, secure, unique and selective organic compounds. Due to their clear mechanism of action on pests and lower poisonousness towards vertebrates than conventional insecticides, juvenile hormone analogues as an example of insect growth regulators appear promising. Thus, a unique set of pure insect growth regulators has been synthesized. The structure of these synthesized compounds, which were related to the most well-known insect growth regulator insecticides, was confirmed by elemental and contemporary spectroscopic investigations (IR, UV, 1 H-NMR, 13 C NMR, and Dept 135 spectrum). Under laboratory conditions, the effectiveness of a chemically newly synthesized products was tested against the cotton mealybug, Phenacoccus solenopsis, and compared with Fenoxycarb as a reference insecticide. Compound 7 was discovered to be more effective than the other synthetic compounds, with LC50 values of 0.907 mg/L for adult female P. solenopsis and 0.377 mg/L for third instar nymphs. Furthermore, this results concluded that the adult female's stage of P. solenopsis was less sensitive to the checked treatments as matched to the third instar nymphs.