Patent ID: 6900215

Claim:
A compound of formula I, or a pharmaceutically acceptable salt thereof: wherein X 1 represents halogen, trifluoromethyl or C 1-6 alkoxy; X 2 represents hydrogen or halogen; Y represents a chemical bond, an oxygen atom, or a —NH— linkage; Z represents an optionally substituted aryl or heteroaryl group; R 1 represents hydrogen, hydrocarbon, a heterocyclic group, halogen, cyano, trifluoromethyl, nitro, —OR a , —SR a , —SOR a , —SO 2 R a , —SO 2 NR a R b , —NR a R b , —NR a COR b , —NR a CO 2 R b , —COR a , —CO 2 R a , —CONR a R b or —CR a ═NOR b ; R 2 represents hydrogen or halogen; and R a and R b independently represent hydrogen, hydrocarbon or a heterocyclic group.