SYNTHESIS AND IN-VIVO EVALUATION OF I-123]IODO-4-OXO-1,4-DIHYDROQUINOLINE-2-CARBOXYLIC ACID

As a possible radioligand for SPECT visualization of the NMDA receptor s in the central nervous system, 7-chloro-5-[I-125]iodokynurenic acid was prepared. This paper presents the synthesis of both the radioactiv e and the non-radioactive product, starting from 5-bromo-7-chlorokynur enic acid and using a non-isotopic nucleophilic halogen exchange react ion in the presence of iodide ((NaI)-I-123 or KI). Under the best labe lling conditions, the radiochemical yield was 85%. The specific activi ty based on UV detection was found to be higher than 1 Ci/mu mol (= 37 GBq/mu mol) and the chemical and radiochemical (>95%) purity of the t racer was checked by RP-HPLC. (C) 1997 Elsevier Science Ltd. All right s reserved.