While studying the anticancer activity of the urethane-type nitrogen mustards, n:e prepared a nuillber of conlpounds of this type fro111 synthetic estrogens, with the purpose of establishing a relationship between the estrogenic activity of the bis-hydroxyphenyl derivatives and the anticancer action of their nitrogen mustard carban~ates. Since com- pounds I and I1 that had previously been prepared (I) exhibited 50-60y0 inhibitions on Walker carcinosarco~na 256 (2), it ...