SYNTHESIS OF [BR-77] ,7-DIBROMO-4-OXO-1,4-DIHYDROQUINOLINE-2-CARBOXYLIC ACID, A POSSIBLE SPECT TRACER FOR NMDA RECEPTOR STUDIES

The synthesis of [Br-77] ,7-dibromo-4-oxo-1,4-dihydroquinoline-2-carbo xylic acid is described. The labelling is performed in order to obtain a tracer for SPECT studies of the N-methyl-D-aspartate receptor in hu man brain. Radiosynthesis was carried out using a non-isotopic nucleop hilic halogen exchange, starting from do-7-bromo-4-oxo-1,4-dihydroquin oline-2-carboxylic acid. In order to obtain the best radiochemical yie ld, several parameters such as reaction temperature, reaction time, am ount of precursor and amount of Cu catalyst were studied. Under the be st labelling conditions, the radiochemical yield was 85 %. The product was found to be chemically and radiochemically pure as determined by HPLC.