New nitrogen mustard analogues in which bis(2-chloroethyl)-amino groups are separated by oxyethylene groups, 1,14-dichloro-3,12-bis(2-chloroethyl)-3,12-diaza-6,9-dioxatetradecan (3c) and 1,17-dichloro-3,15-bis(2-chloroethyl)-3,15-diaza-6,9,12-trioxaheptadecane (3d), were synthesized by reaction of bis(2-hydroxyethyl)amine (2) with bis(2-chloroethyoxy)ethylene (1a) and with 1,11-dichloro-3,6,9-trioxaundecane (1b), respectively, followed by treatment with thionyl chloride. The analogues were then complexed with heparin. The resulting heparin-complexes show inhibiting activity against transplanted Sarcoma-180 A in mice.