cis-4-[[[(2-Chloroethyl)nitrosoamino]carbonyl]methylamino] cyclohexanecarboxylic acid, a nitrosourea with latent activity against an experimental solid tumor.

cis-4-[[[(2-Chloroethyl)nitrosoamino]carbonyl]methylamino] cyclohexanecarboxylic acid (N-Me-cis-CCCNU) was synthesized in five steps from cis-4-aminocyclohexanecarboxylic acid via an N-tosylated intermediate. N-Me-cis-CCCNU, which is incapable of the facile decomposition that characterizes the clinically useful nitrosoureas, effected a significant cure rate of both early and established murine Lewis lung carcinoma, even though its in vitro half-life was approximately 5.5 times that of the unmethylated parent compound. This is the first observation of latent activity of a nitrosourea against an experimental solid tumor.