Carboxylic acid derivatives and drugs containing the same as the active ingredient

A compound of the formula (I)

• (wherein,
• A1 is C1-4 alkylene,
• A2 is C2-8 alkylene, C3-8 alkenylene or C3-8 alkynylene,
• E1 is —O— or —S—,
• E2 is —CH2—, —O—, or —S(O)m—.
• m is 0, 1 or 2,
• each R1 in (R1)n independently, is hydrogen, C1-8 alkyl, halogen, C1-4 alkoxy, C1-4 alkythio, nitro, NR7R8 (in which R7 and R8 each independently, is C1-4 alkyl), cyano, trifluoromethyl, trifluoromethyloxy, carbocyclic ring or heterocyclic ring (in which carbocyclic ring and heterocyclic ring may be substituted with the group selected from C1-4 alkyl, C1-4 alkoxy, halogen or trifluoromethyl),
• R2 is hydrogen, C1-8 alkyl, halogen, C1-4 alkoxy, C1-4 alkythio, nitro, NR7R8 (in which R7 and R8 each independently, is C1-4 alkyl), cyano, trifluoromethyl or trifluoromethyloxy,
• R3 and R4 each independently, is hydrogen or C1-4 alkyl or R3 and R4 taken together with carbon atom to which is attached represents C3-7 cycloalkylene,
• R5 is —COOR9 (in which R9 is hydrogen or C1-4 alkyl) or heterocyclic ring which is equivalent to carboxylic acid,
• is oxazole,
• is phenyl or pyridinyl, and n is 1-3) a non-toxic salt thereof, or a hydrate thereof.