Substituted aniline derivatives useful as histamine H3 antagonists

Disclosed are compounds of the formula or a pharmaceutically acceptable salt thereof, wherein M 1 is M 2 is N; X is a bond, optionally substituted alkylene, alkenylene, —O—, —CH 2 N(R 12 )—, —N(R 12 )CH 2 —, —N(R 12 )—, —NHC(O)—, —OCH 2 —, —CH 2 O—, or —S(O) 0-2 —; and Y is —(CH 2 ) 1-2 —, —C(═O)—, —C(═NOR 13 )— or —SO 0-2 —; or M 1 is N; M 2 is N or CH; X is a bond, alkylene, alkenylene, —C(O)—, —NHC(O)—, —OC(O)— or —S(O) 1-2 —; Y is —(CH 2 ) 1-2 —, —C(═O)— or —SO 0-2 —; and when M 2 is CH, Y is also Y is —O— or —C(═NOR 13 )—; Z is a bond or optionally substituted alkylene or alkenylene; U and W are CH, or one is CH and one is N; R 1 is optionally substituted alkyl, cycloalkyl, aryl, arylalkyl, heteroaryl, heterocycloalkyl; R 2 is optionally substituted alkyl, alkenyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; and the remaining variables are as defined in the specification; and compositions and methods of treating obesity, metabolic syndrome and a cognition deficit disorder, alone or in combination with other agents.