Synthesis, Photochemical Isomerization, and Reversible pH-Dependent Switching of α, β-Unsaturated Hydrazone Derivatives

The article describes a new method for the synthesis of functionalized nitrogen-containing α, β-unsaturated compounds based on the reaction of 3-arylidene-1-pyrrolines with various N-nucleophiles. The proposed method allows the preparation of α, β-unsaturated compounds containing fragments of imine, hydrazone, N-methyleneacetohydrazide, N-methylenehydrazine-1-carboxamide, and N-methylenehydrazine-1-carbothioamide. The proposed method is distinguished by mild reaction conditions and the possibility of using various solvents, including water. The yield of the obtained products reaches 99%. The possibility of selective photoisomerization at the C=C bond was demonstrated, making them candidates for further study as photoswitches. The obtained compounds can be used as pH-activated molecular switches. α, β-Unsaturated hydrazides showed good cytotoxicity toward normal and cancer human cell lines.