New 7-azacoumarin-3-carboxamide phosphonium salts: cytotoxicity and the Wittig olefination

New phosphonium salts synthesized from 5-chloromethyl-8-methyl-7-azacoumarin-3-carboxamides and triphenylphosphine upon the Wittig reaction with aromatic aldehydes give the corresponding 5-styryl-7-azacoumarin derivatives. The cytotoxic activity of some phosphonium salts against cancer cell lines M-HeLa and HuTu-80 is equal to or superior to that of the reference 5-fluorouracil. The IC₅₀ and SI values of the leading compounds exceed those for 5-fluorouracil by a factor of 3.7 and 2.2, respectively.