Patent ID: 6962921

Claim:
A method for the treatment of Alzheimer-type dementia which comprises administering an effective amount of a 2-aryl-8-oxodihydropurine derivative of the formula (Ia): wherein: R 12 and R 22 are the same or different and are an ethyl group, a propyl group or a butyl group; or R 12 is a methyl group, an ethyl group or a propyl group, and R 22 is a phenyl group, a halogenophenyl group, a methoxyphenyl group, a benzyl group, a halogenobenzyl group or a methoxybenzyl group; R 32 is a hydrogen atom; Y 1 is a hydrogen atom, a methyl group or an ethyl group; R 42 is a hydrogen atom, a halogen atom, a methyl group, a methoxy group, a nitro group or a trifluoromethyl group, or a pharmaceutically acceptable acid addition salt thereof, to a mammal in need of such treatment of Alzheimer-type dementia.