Synthesis of analogues of N (2 chloroethyl) N' trans 4 methylcyclohexyl) N nitrosourea for evaluation as anticancer agents

Article abstract of DOI:10.1021/jm00212a019

The superior activity of N (2 chloroethyl) N' (trans 4 methylcyclohexyl) N nitrosourea (MeCCNU) against advanced murine Lewis lung carcinoma in comparisons with the cis form and other nitrosoureas prompted the synthesis of a number of MeCCNU analogues, including several cis trans pairs. The methyl group was replaced by a variety of substituents (CO₂H, CH₂CO₂H, CO₂Me, CH₂OAc, CH₂Cl, OMe); the trans 3 methylcyclohexyl, cis 2 methyl 1,3 dithian 5 yl, cis and trans 2 methyl 1,3 dithian 5 yl tetraoxide, and 1 methylhexyl (open chain) analogues were also prepared. Preliminary tests against murine leukemia L1210 revealed therapeutic indices (ED₅₀/LD₁₀) ranging from 0.26 to 0.79; all but 3 analogues effected 50% cure rates at nontoxic doses, the open chain analogue being one of the least active. In terms of therapeutic index, diequatorial (trans 4) isomers were, with one exception, as active as or, in 4 of the 8 examples, somewhat more active than the corresponding axial equatorial (cis 4) isomers. In this series, 4 of the 5 2-fluoroethyl analogues prepared were clearly inferior to the corresponding 2 chloroethyl analogues.