Synthesis and biological activities of new 1,2,4-triazol-3-one derivatives

New 2-phenacyl-1,2,4-triazol-3-ones were obtained by the reaction of 5-alkyl-1,2,4-triazol-3-ones with alpha-bromoacetophenone in alkaline medium. Selective reduction of the side chain carbonyl group to hydroxy group was achieved with NaBH4. The reaction of some compounds containing a phenolic hydroxyl with 4-toluenesulfonyl chloride or benzyl bromide in the presence of NaOH led to tosylated or benzylated derivatives. The tosylation or benzylation at the alcoholic hydroxyl was carried out in the presence of sodium metal. Some of the newly synthesized compounds revealed an antimicrobial activity; 6 of 14 new compounds that were studied by the National Cancer Institute were found to possess antitumor activity.