| abstract |
A condensed heterocyclic derivative of the formula (I): <CHEM> wherein X is an oxygen atom, a sulfuir atom or R<1>-N< wherein R<1> is a hydrogen atom, a hydrocarbon group which may be substituted or an acyl group which may be substituted; R<2> is a hydrogen atom or a hydrocarbon group which may be substituted; ring A is a benzene ring which may be substituted, k is a whole number of 0 to 3; m is a whole number of 1 to 8; and n is a whole number of 1 to 6, or a salt thereof exhibiting high colinesterase inhibitory activity, and a method for producing the same. |