Synthesis and radiosensitizing activity of benzimidazoles
Li, M.J.; Li, S.Z.; Zhuang, X.L.; Chen, A.; Zhang, H.Q.; Pang, X.C.; Hu, B.
Yao Xue Xue Bao 27(9): 662-666
1992
ISSN/ISBN: 0513-4870 PMID: 1293936 Document Number: 393555
In search for effective radiosensitizer with low neurotoxicity, benzimidazole compounds were synthesized. Reaction of 2-nitrobenzimidazole with ethyl chloroformate yielded ethyl alpha-(2-nitrobenzimidazolyl-1)-formate(1) or ethyl alpha-(2-hydroxybenzimidazolyl-1)-formate(2), depending upon the solvents used. Reaction of 2-nitrobenzimidazole with 1,2-epoxy-3-chloropropane gave a cyclized compound which was confirmed to be benzimidazo(1,2b)-5'-chloromethyl-oxazolidine(3). In attempt to increase hydrophilicity, 1-substituted 2-(3'-pyridyl)-5-nitrobenzimidazoles were prepared by reaction of 2-(3'-pyridyl)-5(6)-nitrobenzimidazole(4) with alkyl epoxides or ethyl chloroacetate. Some of the compounds synthesized were tested for radiosensitizing activity in Ehrlich ascites carcinoma-bearing mice. Preliminary results showed that some compounds have radiosensitizing activity. The radiosensitizing enhancement ratio (SER) of compounds 3, 5 and 6 were found to be 1.50, 1.52 and 1.65 respectively.