Inhibitory effect of some esters of 4-hydroxy-5-nitro-4,5-dihydrothymine on the growth of tumor cells

New analogs of 4-hydroxy-5-nitro-4,5-dihydrothymine, namely 4-acyloxy-5-nitro-4,5-dihydrothymines (where: acyl = acetyl, benzoyl, mono- and dichloroacetyl) were synthesized and tested for their toxicologic and antitumor effects on Ehrlich ascites tumor cells and Ehrlich solid tumor. Best results were found for the mono- and dichloroacetyl derivatives.