Synthesis and antitumor properties of new 2,4-dichlorophenoxy ethers

A series of new compounds incorporating 2,4-dichlorophenoxy nucleus have been synthesized. Reaction of 2,4-dichlorophenoxyacetic acid with thiosemicarbazide in the presence of phosphoryl chloride followed by treatment with phenacylbromides led to the formation of imidazo[2,1-b][1,3,4]thiadiazoles (3). Bischlorophenoxyallyl hydrazides (4) reacted with some of alkenes, azo dyes, aldehydes, and hydrazonoyl chlorides to produce pyrazoles, Schiff bases, and bis-diazo compounds, respectively. 1,3,4-Thiadiazole (10) was obtained by reaction of dichlorophenoxyallyl hydrazides (4b) with carbon disulphide followed by hydrazonoyl chlorides. All compounds were tested for their preliminarily antitumor activity on transplantable murine tumor cell line [Ehrlich ascites carcinoma (EAC)]. Compound 2-{2-[2-(2,4-dichlorophenoxy)acetyl]hydrazono}-N'-(4-fluorophenyl)propanehydrazonoyl chloride (8c) has remarkably decreased the viable EAC cell count as indicated by Trypan Blue dye exclusion test (3%) in comparison to the well known antitumor agent 5-FU (0%).