Substituted pyrazinone melanin concentrating hormone receptor-1 antagonists and methods

A compound of Formula I or a pharmaceutically acceptable salt thereof

• wherein
• is a phenylene ring;
• R1 is Z—Y—X—, wherein
• X is S, —SO— or —SO2—;
• Y is a bond, a 3- to 6-membered cycloalkyl, or an alkylene chain of 2 to 3 carbon atoms optionally substituted with a lower alkyl moiety;
• Z is aryl or heteroaryl, wherein Z may be substituted with 1, 2 or 3 of halo, C1-6 alkyl, C1-3 alkoxy, C1-3 thioalkyl, C1-3 trifluoroalkoxy, trifluoromethyl, cycloalkyl, cycloalkoxy, or heteroaryl;
• R2 is -E-G-(J)m, with m being an integer from 1 to 3;
• E is O or S;
• G is lower alkyl, phenylalkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, cycloalkoxy, alkylcycloalkoxy, or cycloalkoxyalkyl;
• each J is independently hydrogen, OH, CN, —SO2R7, —SR7, —SOR7, lower alkyl, lower alkoxy, CF3, —OCF3, or —COOR5;
• R5 is H, C1-6 alkyl, or cycloalkyl;
• R7 is lower alkyl;
• R3 is C1-6 alkyl, lower cycloalkyl, C1-6 alkoxy, halogen, hydrogen, or —S—C1-6 alkyl;
• R8 and R9 are each independently hydrogen, halogen, or lower alkyl;
• with the proviso that E-G and R3 are not identical unsubstituted lower alkoxy groups;
• and
• when G is lower alkyl and J is H, R3 is not hydrogen;
• and
• prodrugs thereof selected from the group consisting of acetates, pivalates, methylcarbonates, benzoates, amino acid esters, phosphates, malonates, succinates and glutarates;
• and all stereoisomers thereof.