A number of nitrosoureas have been synthesized in order to examine those structural features which lead to optimum interstrand DNA cross-linking as this property may relate to their cytotoxicity and antitumor effects. The compounds include 2-chloroethyl trifluoromethanesulfonate, 5, 2-chloroethyl p-nitrobenzenesulfonate, 2-chloroethyl p- toluenesulfonate, and 2-chloroethyl methanesulfonate. Of these compounds, 5, bearing ...