| abstract |
A compound represented by the formula: wherein Ar represents a group represented by the formula: (wherein Y represents methylene or an oxygen atom, R<SUP>1 </SUP>represents aminosulfonyl, C<SUB>1-6 </SUB>alkylaminosulfonyl, C<SUB>1-6 </SUB>alkylcarbonylamino or C<SUB>1-6 </SUB>alkylsulfonylamino, R<SUP>2 </SUP>represents a hydrogen atom or C<SUB>1-6 </SUB>alkyl, R<SUP>3 </SUP>represents C<SUB>1-6 </SUB>alkyl, and R<SUP>4 </SUP>represents a hydrogen atom or C<SUB>1-6 </SUB>alkyl); X represents a carbonyl group, or a methylene group which may be substituted with a hydroxy group; and L represents an optionally substituted C<SUB>4-5 </SUB>alkylene group, or a salt thereof is provided. |