Novel Approach in the Synthesis of Some Pyrimidines with Eminent Toxicological Effects towards Aphis gossypii (Glover, 1887) and Outstanding Safety against Earthworms (Aporrectodea caliginosa).

This study reports the synthesis and bioevaluation of ten novel pyranothiazolopyrimidine derivatives. Their insecticidal efficacy against Aphis gossypii (Glover, 1887) revealed compounds 3 and 10 as lead candidates, exhibiting toxicity comparable to the commercial standard acetamiprid insecticide. Notably, these compounds demonstrated a markedly safer ecotoxicological profile toward the earthworms (Aporrectodea caliginosa), with LC50 values orders of magnitude higher than acetamiprid over 5- and 10-day exposures. Application also induced measurable changes in soil chemistry. These findings identify compounds 3 and 10 as promising insecticidal agents that combine potent aphid toxicity with significantly reduced nontarget risk, highlighting their potential for further development.