Heterocyclic compounds for the inhibition of PASK

A compound having structural formula IV:

• or a salt, ester or prodrug thereof, wherein:
• Rz is OH;
• R1 is chosen from aryl and heteroaryl, either of which may be optionally substituted with one or more substituents selected from the group consisting of hydrogen, halo, alkyl, alkenyl, alkynyl, cycloalkyl, haloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, heteroarylalkyl, CN, alkoxy, alkylamino, dialkylamino, NHSO2R12, NHSO2NHR12, NHCOR12, NHCONHR12, CONHR12, CONR12aR12b, hydroxy, SO2R12, SO2NHR12, CF3, and OCF3;
• R3 is hydrogen;
• R5 and R6 are independently selected from the group consisting of hydrogen, C1-C6 alkyl, C1-C7 cycloalkyl, C1-C7 heterocycloalkyl, C1-C6 alkenyl, C1-C6 alkynyl, aryl, heteroaryl, aralkyl, and heteroaralkyl, or taken together, R5 and R6 may form a heterocycloalkyl or heteroaryl, any of which may be optionally substituted;
• and
• R12, R12a and R12b are independently selected from the group consisting of hydrogen, C1-C6 alkyl, aryl, heteroaryl, aralkyl, CF3 and heteroaralkyl, any of which may be optionally substituted.