Studies on Antitumor-active 2, 3-Dioxopiperazine Derivatives. I. Degradation Products of 1-(2-Chloroethyl)-3-(4-substituted-2, 3-dioxo-1-piperazinyl)-alkyl-1-nitrosourea in Aqueous Solution

Abstract

Degradation products of 1-(2-chloroethyl)-3-(4-substituted-2, 3-dioxo-1-piperazinyl)-alkyl-1-nitrosourea in aqueous solution were investigated. Among them, a symmetrical urea derivative, 1, 3-bis [4-(4-ethyl-2, 3-dioxo-1-piperazinyl) butyl] urea (3c), was found to have antitumor activity. A synthetic unsymmetrical urea derivative, 1-[2-(4-ethyl-2, 3-dioxo-1-piperazinyl) ethyl]-3-methylurea (4a), also showed antitumor activity against Ehrlich carcinoma (solid form).