Синтез та біологічна активність 2-ариліден-5,6-дигідроімідазо[2,1-b]тіазолів і 6,7-дигідро-5h-[1,3]тіазоло[3,2-a]піримідинів

The aim. The present study is devoted to searching for potential biologically active agents among functionalized imidazo[2,1-b]thiazoles and thiazolo[3,2-a]pyrimidines. Materials and methods. The interaction of preparatively available 5,6-dihydroimidazo[2,1-b]thiazolone and 6,7-dihydro-2H-thiazolo[3,2-a]pyrimidinone with several substituted benzaldehydes in boiling acetic acid in the presence of anhydrous sodium acetate leads to new 2-arylidene-substituted 5,6-dihydroimidazo[2,1-b]thiazoles and 6,7-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidines as potential pharmacological agents. Their antimicrobial activity was studied using the micromethod of two-fold serial dilutions in a liquid nutrient medium. The antioxidant activity of the synthesized compounds was evaluated using a DPPH assay. Results. A library of 2-arylidene-5,6-dihydroimidazo[2,1-b]thiazolone and 6,7-dihydro-2H-thiazolo[3,2-a]pyrimidinone was synthesized by condensation of 5,6-dihydroimidazo[2,1-b]thiazoles and 6,7-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidines with series of aromatic aldehydes. Pharmacological in vitro screening results revealed that synthesized compounds possess moderate antimicrobial activity with MBC and MFC values of 31.25-62.5 mg/mL. While studying the antioxidant activity, it was found that all derivatives effectively inhibited DPPH radicals with an inhibition rate of 42.3-94.4 %. The best antiradical effect was observed for the molecule's derivatives containing 3-methoxy-4-hydroxy- or 2-hydroxyphenylmethylidene fragments. Conclusions. It was found that the Knevenagel condensation of 5,6-dihydroimidazo[2,1-b]thiazolone and 6,7-dihydro-2H-thiazolo[3,2-a]pyrimidinone with aromatic aldehydes is a convenient approach for structure modification and optimization using pharmacophore fragments for these types of heterocycle. The synthesized arylidene derivatives are characterized by moderate antimicrobial and good antioxidant activity in vitro models