Patent ID: 8344002

Claim:
A compound represented by the following formula (1): wherein Ar is a substituted or unsubstituted 5 to 6 membered mono cyclic aromatic group, and said aromatic group may have a hetero atom selected from nitrogen atom, oxygen atom and sulfur atom; R 1 , R 2 and R 3 are hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted allyl group, or substituted or unsubstituted aryl group, nitro group, halogen atom, cyano group, hydroxy group, or carboxy group, and R 2 and R 3 may be taken together with the adjacent nitrogen atom and carbon atom respectively to form a 3 to 6 membered ring which may be interrupted by oxygen atom, sulfur atom or substituted or unsubstituted amino group; R 4 is C 1-6 alkyl group, C 2-6 alkenyl group, C 2-6 alkinyl group, C 3-7 cycloalkyl group, phenyl group, C 1-6 alkyl group substituted by phenyl, phenylthio or a hetero ring provided that said phenyl, said phenylthio and said hetero ring may be substituted by C 1-6 alkyl, hydroxy, nitro, halogen, —SO 3 H or —PO 4 H; A is represented by the formula: wherein X and Y are oxygen atom, NH or sulfur atom, Z is hydrogen atom, hydroxy group, amino group, or thiol group, and when Z is hydroxy group, amino group or thiol group, said group may be substituted by substituted or unsubstituted alkyl group, substituted or unsubstituted allyl group, or substituted or unsubstituted aryl group, substituted or unsubstituted acyl group, substituted or unsubstituted alkylsulfonyl group, substituted or unsubstituted arylsulfonyl group, or substituted or unsubstituted allylsulfonyl group; and B is hydroxy group, substituted or unsubstituted amino group, substituted or unsubstituted hydrazino group, substituted or unsubstituted hydroxyamino group, or substituted or unsubstituted aliphatic or aromatic amino group, or its pharmaceutically acceptable salt.