Synthesis of New Diffractaic Acid Derivatives and a Study of their Activity Against the Strain A2 RSV

We report a two-step synthesis of benzyl diffractate ethers through the preparation of intermediate benzyl diffractate ethers with an alkyl substituent containing a terminal bromine atom. A series of new diffractaic acid based ethers are synthesized by replacing the bromine atom with various N- and S-nucleophiles. It is shown that benzyl diffractate derivatives exhibit pronounced antiviral in vitro activity against the strain A2 respiratory syncytial virus in a low micromolar concentration range. The dependence of the antiviral activity and cytotoxicity on the compound structure is determined. The analysis of biological activity data revealed two compounds of the active antiviral agents category with the selectivity indices 11.0 and 31.3.