Patent ID: 8327467

Claim:
An anthranilic acid compound, or a salt thereof, according to the following general formula: wherein R 1 represents a hydrogen atom or a carboxyl protecting group; R 2 represents a hydrogen atom or an imino protecting group; R 3 represents a a phenyl, or a cycloalkyl which may be substituted with one or more substituents selected from the following group of substituents (1); R 4 represents a phenyl, which may be substituted with one or more substituents selected from the following groups of substituents (2) and (3); or a pyridyl group which may be substituted with one or more substituents selected from the following groups of substituents (2) and (4); X 1 represents an alkylene or alkenylene group or a bond; and X 2 represents a bond, a carbonyl linking group or a linking group selected from the following linking groups —X 3 —X 4 —, —X 4 —X 3 —, —O—X 4 — or —X 4 —C(O)NH—, with the proviso that the bond on the left side of the linking group binds to R 4 , wherein X 3 represents a sulfur atom, an imino group which may be protected, a sulfinyl group, a sulfonyl group or a bond, and X 4 , wherein both X 3 and X 4 cannot simultaneously be a bond; said group of substituents (1) represents a halogen atom, a cyano group, a nitro group, an acyl group, an alkanesulfonyl group, an alkanesulfonamide group, an acetamido group, a carbamoyl group, a sulfamoyl group, a lower alkylamino group, an amino group which may be protected, a hydroxyl group which may be protected, an alkyl group which may be substituted, an alkenyl group which may be substituted, an alkynyl group which may be substituted, an alkoxy group which may be substituted, an aryl group which may be substituted, a cyclic amino group which may be substituted, an aralkyl group which may be substituted or a heterocyclic group which may be substituted; said group of substituents (2) represents an alkyl, alkenyl, alkynyl, alkoxy, aryl, cyclic amino, aralkyl or heterocyclic group which may be substituted with one or more groups selected from a halogen atom, a cyano group, a nitro group, an amino group, a cyclic amino group, a lower alkylamino group, a carboxyl group, a hydroxyl group, a lower alkyl group, an alkoxy group and an aryl group; said group of substituents (3) represents a halogen atom, a cyano group, a nitro group, an acyl group, an alkanesulfonyl group, an alkanesulfonamide group, an acetamido group, a carbamoyl group, a sulfamoyl group, a lower alkylamino group, an amino group which may be protected or a hydroxyl group which may be protected; and said group of substituents (4) represents a cyano group, a nitro group, an acyl group, an alkanesulfonyl group, an alkanesulfonamide group, an acetamido group, a carbamoyl group, a sulfamoyl group, a lower alkylamino group, an amino group which may be protected or a hydroxyl group which may be protected.