Compounds for binding and imaging amyloid plaques and their use

A Compound of formula I

• for use as diagnostic agent or imaging agent for imaging diseases associated with beta amyloid deposits
• wherein
• R1 is H, phenyl or X;
• R2 is H, OCH3, N(CH3)2, O—(CH2)n—X;
• (CH2)n—X or X;
• R3 is H;
• R4 is H or Br;
• X is F or 18F;
• Y is CH, CCN, CCF3 or N;
• and
• n is 1, 2 or 3;
• with the proviso that one of the substituents R1 and R2 comprises 18F or is 18F,
• or an isomeric form of said compound;
• and pharmaceutically acceptable salts and salt complexes thereof.