Abstract: Two title compounds, which are nuclear alkylated ortho isomers of CUI XING AN, were prepared and tested for anticholinesterase activity and other actions. Preliminary results indicated that introduction of a t-butyl group on the benzene ring lowered toxicity and anticholinesterase activity.Monoetherification of 4-t-butyl pyrocatechol with 2-dimethylamino ethyl chloride yielded a mixture of 4-t-butyl and 5-t-butyl-2-(2-dimethylamino) ethoxy phenol (Ⅳ₁ and Ⅳ₂) in approximately equal proportions. The hydro chlorides of the two isomers could be separated by fractional crystallization from methanol. Their structures were characterized.