The present invention provides a compound represented by the formula (I) ##STR00001## wherein R.sup.1 is a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, an optionally substituted hydroxy group, an optionally substituted thiol group or an optionally substituted amino group, A is an optionally substituted cyclic amino group or --NR.sup.2--W--D wherein R.sup.2 is a hydrogen atom or an alkyl group, W is a bond or a divalent acyclic hydrocarbon group, and D is an optionally substituted cyclic group, an optionally substituted amino group or an optionally substituted acyl group, B is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, X is an oxygen atom, a sulfur atom or an optionally substituted nitrogen atom, and Y is a bond or a divalent acyclic hydrocarbon group, or a salt thereof, which is useful for the prophylaxis or treatment of diabetic neuropathy and the like.