Patent ID: 8044090

Claim:
A method of treating Alzheimer's disease comprising administering to a patient in need thereof an effective amount of a combination of a 5-HT 6 receptor antagonist and a cholinesterase inhibitor, or pharmaceutically acceptable salts thereof, wherin the 5-HT 6 receptor antagonist is of structural formula I: wherein X is selected from the group consisting of —O—, —NH—, —S—, —SO 2 —, —CH 2 —, —CH(F)—, —CH (OH)—, and —C(O)—; R 1 is selected from the group consisting of optionally substituted phenyl, optionally substituted naphthyl, optionally substituted 5 to 6 membered monocyclic aromatic heterocycle having one heteroatom selected from the group consisting of nitrogen, oxygen, and sulfur and which 5 to 6 membered monocyclic aromatic heterocycle is optionally benzofused; R 2 is selected from the group consisting of hydrogen and C 1 -C 3 alkyl; R 3 is selected from the group consisting of hydrogen, fluoro, and methyl; and R 4 is selected from the group consisting of hydrogen, allyl, C 2 -C 4 alkyl, fluorinated C 2 -C 4 alkyl, optionally substituted phenyl, optionally substituted phenylsulfonyl, optionally substituted benzyl, and optionally substituted 5 to 6 membered monocyclic aromatic heterocycle having one or two heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur, provided that R 4 is not optionally substituted phenylsulfonyl when X is —SO 2 —, —CH 2 —, —CH(F)—, —CH(OH)—, or —C(O)—.