A compound of Formula I, or a pharmaceutically acceptable salt or solvate thereof, wherein: A represents =S, -SR 4 or =O; X represents F, Cl, Br or I; R 1 represents phenyl, a phenyl-C 1 -C 6 alkyl, a 5- or 6-membered heterocyclic ring, or a substituted heterocyclic ring; when R 1 represents a phenyl-C 1 -C 6 alkyl, wherein the phenyl is unsubstituted or substituted with 1-4 substituents independently selected from the group consisting of: halogen, nitro, hydroxyl, amino, cyano, a C 1 -C 6 alkyl, a C 1 -C 6 alkoxy, and a C 1 -C 6 haloalkyl, wherein the alkyl, alkoxy and haloalkyl may be optionally substituted with hydroxyl, a -O-(C 1 -C 4)-alkyl, oxo, amino, a -NH-(C 1 -C 4)-alkyl, or a -N-[(C 1 -C 6)-alkyl] 2, or the alkyl, alkoxy and haloalkyl are optionally intervened by -O-, -S-, -NH-, -COO-, or -CONH-; when R 1 represents a 5- or 6-membered heterocyclic ring, or a substituted heterocyclic ring, wherein the heterocyclic ring is unsubstituted or substituted with 1-3 substituents independently selected from the group consisting of: halogen, nitro, hydroxyl, amino, cyano, a C 1 -C 6 alkyl, a C 1 -C 6 alkoxy, and a C 1 -C 6 haloalkyl, and wherein the alkyl, alkoxy and haloalkyl may be optionally substituted with hydroxyl, a -O-(C 1 -C 4)-alkyl, oxo, amino, a -NH-(C 1 -C 4)-alkyl, or a -N-[(C 1 -C 6)-alkyl] 2, or the alkyl, alkoxy and haloalkyl are optionally intervened by -O-, -S-, -NH-, or -COO-, and the heterocyclic ring may be a nitrogen nitrogen heterocyclic ring, nitrogen oxygen heterocyclic ring, or nitrogen sulfur heterocyclic ring; R 2, and R 3 represent hydrogen, a C 1 -C 6 alkyl, a C 3 -C 6 cycloalkyl, a C 1 -C 6 alkoxy C 1 -C 6 alkyl, an amino C 1 -C 6 alkyl, a phenyl C 1 -C 6 alkyl, a heterocyclic C 1 -C 6 alkyl, phenyl, or a C 1 -C 6 heterocyclic group, wherein R 2 and R 3 may be attached together to form a ring; and R 4 represents C 1 -C 6 alkyl. A represents =S, -SR 4 or =O; X represents F, Cl, Br or I; R 1 represents phenyl, a phenyl-C 1 -C 6 alkyl, a 5- or 6-membered heterocyclic ring, or a substituted heterocyclic ring; when R 1 represents a phenyl-C 1 -C 6 alkyl, wherein the phenyl is unsubstituted or substituted with 1-4 substituents independently selected from the group consisting of: halogen, nitro, hydroxyl, amino, cyano, a C 1 -C 6 alkyl, a C 1 -C 6 alkoxy, and a C 1 -C 6 haloalkyl, wherein the alkyl, alkoxy and haloalkyl may be optionally substituted with hydroxyl, a -O-(C 1 -C 4)-alkyl, oxo, amino, a -NH-(C 1 -C 4)-alkyl, or a -N-[(C 1 -C 6)-alkyl] 2, or the alkyl, alkoxy and haloalkyl are optionally intervened by -O-, -S-, -NH-, -COO-, or -CONH-; when R 1 represents a 5- or 6-membered heterocyclic ring, or a substituted heterocyclic ring, wherein the heterocyclic ring is unsubstituted or substituted with 1-3 substituents independently selected from the group consisting of: halogen, nitro, hydroxyl, amino, cyano, a C 1 -C 6 alkyl, a C 1 -C 6 alkoxy, and a C 1 -C 6 haloalkyl, and wherein the alkyl, alkoxy and haloalkyl may be optionally substituted with hydroxyl, a -O-(C 1 -C 4)-alkyl, oxo, amino, a -NH-(C 1 -C 4)-alkyl, or a -N-[(C 1 -C 6)-alkyl] 2, or the alkyl, alkoxy and haloalkyl are optionally intervened by -O-, -S-, -NH-, or -COO-, and the heterocyclic ring may be a nitrogen nitrogen heterocyclic ring, nitrogen oxygen heterocyclic ring, or nitrogen sulfur heterocyclic ring; R 2, and R 3 represent hydrogen, a C 1 -C 6 alkyl, a C 3 -C 6 cycloalkyl, a C 1 -C 6 alkoxy C 1 -C 6 alkyl, an amino C 1 -C 6 alkyl, a phenyl C 1 -C 6 alkyl, a heterocyclic C 1 -C 6 alkyl, phenyl, or a C 1 -C 6 heterocyclic group, wherein R 2 and R 3 may be attached together to form a ring; and R 4 represents C 1 -C 6 alkyl.