Synthesis and radioprotective activity of WR-1065 derivatives: N-(2-acetylthioethyl)-1,3-propanediamine and N,N′-bis(2-acetylthioethyl)-1,3-propanediamine

N-(2-Acetylthioethyl)-1,3-propanediamine (13a, as its 2HBr salt, or 13b, as its 2CF3CO2H salt) and N,N′-bis(2-acetylthioethyl)-1,3-propanediamine (16, as its 2CF3CO3H salt) have been prepared and evaluated as potential radioprotectors in mice. Their toxicity and radioprotective activity (survival rate) have been determined and compared with that of WR-2721. Intermediate N-(2-acetylthioethyl)-N,N′-bis(Z or Boc)-1,3-propanediamines were prepared in two ways from the corresponding alcohols. The most convenient method (the Mitsunobu procedure) was used to obtain the N,N′-bis(2-acetylthioethylated) derivative from the corresponding diol. Surprisingly, none of these compounds possesses radioprotective activity.