Synthesis, reactions, and antioxidant activity of 3-(pyrrol-1-yl)-4,6-dimethyl selenolo[2,3-b]pyridine derivatives

Functionalized Pyridines: Synthesis and Toxicity Evaluation of Potential Insecticidal Agents against Aphis craccivora

Using ultrasound technology instead of traditional methods, some pyridine derivatives were prepared by a simple procedure via a four-component reaction of different aromatic aldehydes, acetyl aryl, sodium alkoxide, and malononitrile, and additionally, all prepared compounds were monitored for insecticidal activities toward nymphs and adults of cowpea aphid. Though a lot of insecticides are discovered as a novelty on the other hand, neonicotinoid compounds are reflected as the most affected insecticides against aphids and many other pests. Thus, some of the pyridine derivatives were chemically prepared as analogues to a large group of insecticides called neonicotinoids. Under laboratory conditions, the toxicity of these components was measured toward adults and nymphs of Aphis craccivora. With respect to the LC50 values, components 1f, 1d, and 1c have the utmost insecticidal bioactivity, with values of 0.080, 0.098, and 0.127 mg/L. This work covers the way to discover novel compounds for the prospective use as insecticidal representatives.

Abdel-Raheem SA. Design, Synthesis, Characterization, and Insecticidal Bioefficacy Screening of Some New Pyridine Derivatives

A lot of insecticides are found nowadays, but neonicotinoids are considered the most famous. So, a series of pyridine derivatives neonicotinoids analogues, namely, 3-cyano-4,6-dimethylpyridine-2(1H)-one (1), 2-chloro-3-cyano-4,6-dimethylpyridine (2), 3-cyano-4,6-dimethylpyridine-2(1H)-thione (3), 3-cyano-4,6-distyrylpyridine-2(1H)-thione (4), 2-((3-cyano-4,6-distyrylpyridin-2-yl)thio)-N-phenylacetamide (5), 3-amino-N-phenyl-4,6-distyrylthieno[2,3-b]pyridine-2-carboxamide (6), 2-((3-cyano-4,6-distyrylpyridin-2-yl)thio)-N-(p-tolyl)acetamide (7), 3-amino-4,6-distyryl-N-(p-tolyl)thieno[2,3-b]pyridine-2-carboxamide (8), 2-((3-cyano-4,6-distyrylpyridin-2-yl)thio)-N-(4-methoxyphenyl)acetamide (9), and 3-amino-N-(4-methoxyphenyl)-4,6-distyrylthieno[2,3-b]pyridine-2-carboxamide (10), have been designed and synthesized in pure state, and their agricultural bioefficacy as insecticides against cowpea aphid Aphis craccivora Koch was screened. The structures of the synthesized compounds were verified by means of spectroscopic and elemental analyses. Insecticidal bioefficacy data illustrated that some compounds are excellent against cowpea aphid, and the bioefficacy of the rest of the tested compounds ranged from good to moderate against the same insects.