Reverse amide compounds as protein deacetylase inhibitors and methods of use thereof

A compound of formula I:

• or a pharmaceutically acceptable salt, ester or prodrug thereof,
• wherein,
• Z is N;
• ring A is phenyl, pyridinyl, pyrazinyl, indolyl, imidazolyl, oxazolyl, furyl, thienyl, thiazolyl, triazolyl, isoxazolyl, quinolinyl, pyrrolyl, pyrazolyl, or 5,6,7,8-tetrahydroisoquinoline;
• all of which may be optionally substituted with halo;
• ring B is aryl or heteroaryl;
• wherein aryl or heteroaryl may be optionally substituted with alkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, aralkyl, haloalkyl, halo, OH, NH2, NHR″, CN, or NO2;
• R1 is H, alkyl, haloalkyl, alkenyl, aryl, arylalkyl, heteroaryl, heterocyclic, or carbocyclic, wherein aryl and heteroaryl may be optionally substituted with OH or halo;
• R is H or alkyl;
• R″ is H or C1-12 alkyl;
• and
• n is 4, 5, 6, 7, or 8.