Hydroxamic acid compounds

Abstract From the Canadian patent

A compound of the following formula:, (see fig. I) and its pharmaceutically acceptable salt thereof wherein, R1 and R~ are independently hydrogen C1-4 alkyl, C3-7 cycloalkyl, C2-4 alkenyl,C1-4 alkoxy-C1-4 alkyl C1-4 alkylthio-C1-4 alkyl, phenyl, phenyl-C1-4alkyl halo-substituted C1-4 alkyl, C3-7 cycloalkyl-C1-3 alkyl or hydroxy-C1-4alkyl; or R1 and R~ are taken together with the nitrogen to which they are attached and form optionally substituted, saturated or unsaturated 3- 4-, 5-, 6- or 7- membered, heterocyclic containing one to two heteroatoms provided that the heterocyclic, is not pyrrolidinyl; R3 is hydrogen, C1-4 alkyl or a hydroxy protecting group; Ar is optionally substituted phenyl …