Toxicity of a Homologous Series of 2-Alkyl-5-methylbenzimidazoles in Chick Embryos.

Summary The effect of eight 2-alkyl-5-methylbenzimidazole homologues with chain lengths ranging from 2 to 16 carbons on the mortality of 6-day chick embryos was investigated. Comparing compounds on a weight basis, it was found that the toxicity of the ethyl homologue was approximately 5 times greater than that of any of the other homologues and that, with the exception of propyl, as the chain length increased, the toxicity decreased. The propyl homologue was less toxic than the butyl, amyl, or heptyl homologues. A linear relationship between dose level and toxicity for each of the compounds was demonstrated.