Patent ID: 7417060

Claim:
A compound of the formula [I]: wherein X is a bond, —CH 2 —, —O—, or —NH—, R 1 and R 12 are each independently hydrogen, halogen, lower alkyl, hydroxy, lower alkoxy, benzyloxy, nitro, amino, or (lower alkylsulfonyl)amino, R 2 is hydrogen or optionally substituted lower alkyl, R 3 is hydrogen or an amino protective group, R 4 , R 5 , and R 6 are each independently hydrogen or optionally substituted lower alkyl, R 7 is -Z-R 13 , in which Z is a bond or —(CH 2 ) n — (in which n is 1), and R 13 is (lower alkylsulfonyl)carbamoyl or lower alkanoylsulfamoyl, R 8 is —Y—R 9 , in which Y is a bond, —CH 2 —, —O—, —S—, —SO—, —SO 2 —, —NH—, or in which R 10 is lower alkyl, cyclo(lower)alkyl, or aryl), and R 9 is hydrogen, lower alkyl, cyclo(lower)alkyl, mono(or di or tri)halo(lower)alkyl, lower alkanoyl, lower alkenyl, lower alkoxy(lower)alkyl, nitro, aryl, or a heterocyclic group, and R 11 is hydrogen, lower alkyl, lower alkoxy, amino or mono(or di)lower(alkyl)amino, or a salt thereof.