Patent ID: 7253154

Claim:
Compounds of the following formula (I) or salts thereof in which R 1 represents an alkyl group having 1-8 carbon atoms, an alkyl group substituted with 1-3 halogen atoms, OR 4 , CO 2 R 5 , or; S(O) n R 6 wherein R 4 is hydrogen, or an alkyl group having 1-8 carbon atoms, an aralkyl group having an aryl moiety of 6-10 carbon atoms and an alkyl moiety of 1-4 carbon atoms, an alkylcarbonyl group having 2-9 carbon atoms, an arylcarbonyl group having an aryl moiety of 6-10 carbon atoms, an aralkylcarbonyl group having an aryl moiety of 6-10 carbon atoms and an alkylcarbonyl moiety of 2-5 carbon atoms or an aryl group having 6-10 carbon atoms which may have a substituent selected from the group consisting of halogen, hydroxyl, nitro and cyano; each of R 5 and R 6 is hydrogen or an alkyl group having 1-8 carbon atoms, an aralkyl group having an aryl moiety of 6-10 carbon atoms and an alkyl moiety of 1-4 carbon atoms, or an aryl group having 6-10 carbon atoms which may have a substituent selected from the group consisting of halogen, hydroxyl, nitro, cyano and amino; and n is an integer of 0 to 2; R 2 is hydrogen, halogen, nitro, cyano, formyl, an alkyl group having 1-8 carbon atoms, an alkyl group having 1-8 carbon atoms which is substituted with one to three halogens, or CO 2 R 7 wherein R 7 has the same meaning as R 5 above; R 3 is hydrogen, halogen, hydroxyl, amino, CO 2 R 8 , PO(OH)(OR 9 ), S(O) m R 10 , or an alkyl group having 1-8 carbon atoms or an alkylaminocarbonyl group having alkyl of 1-8 carbon atoms which may have a substituent selected from the group consisting of halogen, hydroxyl, nitro, cyano and amino; wherein each of R 8 , R 9 , and R 10 has the same meaning as R 5 above; m has the same meaning as n above; X is sulfur; and each of Y and Z is nitrogen.