Purinone derivatives for treating neurodegenerative diseases

A compound of formula:

• wherein
• R1 is selected from lower alkyl lower alkyloxyalkyl, arylalkyl, aryl, substituted aryl and substituted arylalkyl;
• X is selected from NR2a and O;
• R2 is selected from H, C1-C20 hydrocarbon, C1-C20acyl, heterocyclyl other than 2-pyridinyl and 1-imidazolyl, heterocyclylalkyl, substituted alkyl, substituted aryl, substituted heterocyclyl, substituted arylalkyl and substituted heterocyclylalkyl;
• R2Ais selected from H and C1-C10 hydrocarbon;
• or R2 and R2Atogether form a 5-7 membered heterocycle or substituted 5-7 membered heterocycle;
• and
• R3 is selected from H, lower alkyl arylalkyl, heterocyclyl, substituted heterocyclyl, heterocyclylalkyl and substituted arylalkyl;
• with the provisos that
• (i) at least one of R1, R2 and R3 must provide an aryl or heteroaryl moeity;
• (ii) when R3 is H, R1 must be other than lower alkyl;
• (iii) when X is NR2A, R2Ais H, and R1 is phenyl or tolyl, then R2 must be other than phenyl and tolyl;
• and
• (iv) R2 is not p-chlorophenethyl.