1-Aryl-3-(2-chloroethyl) ureas: synthesis and in vitro assay as potential anticancer agents.

1-Aryl-3-(2-chloroethyl) ureas and 1-aryl-3-nitroso-3-(2-chloroethyl) ureas, derived from 4-phenylbutyric acid and alkylanilines, were synthesized and their cytotoxicity was evaluated on human adenocarcinoma cells in vitro. Methyl 4-[p-[3-(2-chloroethyl)ureido]-phenyl]butyrate, 4-methyl [3-(2-chloroethyl)ureido]benzene, and 4-butyl[3-(2-chloroethyl)ureido]benzene were found to be at least as cytotoxic as 4-[p-[bis-(2-chloroethyl)amino]phenyl]butyric acid (chlorambucil), while their N-nitroso derivatives were inactive.