Patent ID: 8586571

Claim:
A compound represented by the formula wherein ring A is benzene optionally further substituted; R 1 is an optionally substituted branched C 3-6 alkyl group; X 1 is O, S, SO, SO 2 or NH; X 2 is a bond or a C 1-3 alkylene group; ring B is azetidine; X 3 is CO or SO 2 ; R 2 is an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, an optionally substituted hydroxy group, an optionally substituted mercapto group, a cyano group, a nitro group, an acyl group, or a halogen atom, provided that when X 3 is CO, then R 2 is not a tert-butoxy group, or a salt thereof.