MCH antagonists and their use in the treatment of obesity

A compound represented by the structural formula

• or a pharmaceutically acceptable salt thereof, wherein
• m is 1;
• n is 1;
• X1 is N;
• X2is N—R5;
• X3 is O or N—R6;
• X4 is NH, N—R7 or N, and when X4 is N, R2 and X4 can join together to form a heterocycloalkyl group wherein said heterocycloalkyl group is piperidine, pyrrolidine, morpholine, piperazine, thiomorpholine,
• where the N of X4 is the heteroatom of said heterocycloalkyl group, wherein said heterocycloalkyl group can be optionally substituted with one or more alkyl, aryl, aralkyl, or cycloalkylalkyl;
• Ar is an arylene group;
• R is R4-phenyl, R4-pyridyl, R4-pyridyl-N-oxide, or R4-pyrimidyl;
• R1 is hydrogen or (C1-C3)alkyl;
• R2 is R8-phenyl;
• R3 is hydrogen, OH, —O(C1-C3)alkyl, or non-substituted or halosubstituted (C1-C3)alkyl;
• R4 and R8 maybe the same or different, may number 0 to 3, each being independently selected from the group consisting of hydrogen, —(C1-C6)alkyl, —(C3-C7)cycloalkyl, halo, —CN, (C1-C6)alkoxy, —CF3, —OCF3, —CONH2, —CONH(C1-C6)alkyl, —CON(C1-C6)alkyl (C1-C6)alkyl, —NH2, —NHC(O)(C1-C6)alkyl, —NHC(O)NH(C1-C6)alkyl, —NHC(O)N((C1-C6)alkyl)((C1-C6)alkyl), —NHSO2(C1-C6)alkyl, —S(C1-C6)alkyl, —SO(C1-C6)alkyl, —SO2(C1-C6)alkyl, —SO2NH(C1-C6)alkyl, —O(C1-C3)alkyleneO—, and NO2 or two adjacent R4 or two adjacent R8 groups together may form a methylenedioxy, propylenedioxy or ethylenedioxy group;
• R5 is hydrogen, nonsubstituted or halosubstituted —(C1-C6)alkyl, or nonsubstituted or halosubstituted (C3-C7)cycloalkyl;
• R6 and R7 may be the same or different, each being independently selected from hydrogen, nonsubstituted or halosubstituted (C1-C3)alkyl;
• or R6 and R7 can be joined together to form an imidazolone ring.