Use of novel compound having affinity for amyloid, and process for production of the same

A process for production of a radioactive halogen-labeled organic compound, which comprises a step of preparing a reaction solution containing, together with a radioactive halogen ion, a compound represented by the following formula (2) or a salt thereof:

• wherein A1, A2, A3 and A4 independently represent a carbon or a nitrogen, and R4 is a group represented by the following formula:
• wherein m is an integer of 0 to 4;
• n is an integer of 0 or 1;
• and
• when m=n=0, R2 is a non-radioactive halogen substituent, nitro substituent, trialkylammonium substituent having 3 to 12 carbon atoms, trialkylstannyl substituent having 3 to 12 carbon atoms or triphenylstannyl substituent, and when m≠0 and/or n≠0, R2 is a non-radioactive halogen substituent, methanesulfonyloxy substituent, trifluoromethanesulfonyloxy substituent or aromatic sulfonyloxy substituent, provided that at least one of A1, A2, A3 and A4 represents a carbon, and R4 binds to a carbon represented by A1, A2, A3 or A4;
• and
• a step of giving a reaction condition to the above reaction solution to synthesize a compound represented by the following formula:
• wherein A1, A2, A3 and A4 are the same as in the formula (2), and R3 is a group represented by the following formula:
• wherein R1 is a radioactive halogen substituent;
• and
• m and n are the same as in the formula (2),
• provided that at least one of A1, A2, A3 and A4 represents a carbon, and R3 binds to a carbon represented by A1, A2, A3 or A4.

The precursor compound for preparing a radioactive halogen-labeled organic compound, which is represented by the following formula (1), or a salt thereof:

• wherein A1, A2, A3 and A4 independently represent a carbon or a nitrogen, and
• R4 is a group represented by the following formula:
• wherein m is an integer of 0 to 4;
• n is an integer of 0 or 1;
• and
• when m=n=0, R2 is a non-radioactive halogen substituent, nitro substituent, trialkylammonium substituent having 3 to 12 carbon atoms, trialkylstannyl substituent having 3 to 12 carbon atoms or triphenylstannyl substituent, and when m≠0 and/or n≠0, R2 is a non-radioactive halogen substituent, methanesulfonyloxy substituent, trifluoromethanesulfonyloxy substituent or aromatic sulfonyloxy substituent,
• provided that at least one of A1, A2, A3 and A4 represents a carbon, and R4 binds to a carbon represented by A1, A2, A3 or A4.