Novel one-pot one-step synthesis of 2'-[(18)F]fluoroflumazenil (FFMZ) for benzodiazepine receptor imaging.
We describe the synthesis of 2'-[(18)F]fluoroflumazenil (FFMZ), which differs from the typically used [(18)F]fluoroethylflumazenil (FEFMZ) for benzodiazepine receptor imaging. For one-pot one-step labeling, the precursors, 2'-tosyloxyflumazenil (TFMZ) and 2'-mesyloxyflumazenil (MFMZ), were synthesized in three steps. The precursors were successfully labeled with no-carrier-added (18)F-fluoride which was activated by repeated azeotropic distillation with Kryptofix 2.2.2./potassium carbonate in MeCN. An automated system for labeling and purification of [(18)F]FFMZ was developed. Labeling efficiency and radiochemical purity of [(18)F]FFMZ after synthesis by the automated system were 68% and 98%, respectively. Specific binding of [(18)F]FFMZ to central benzodiazepine receptor of rats was demonstrated by phosphoimaging.
Yoon
Young Hyun
YH
Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, South Korea.
Jeong
Jae Min
JM
Kim
Hyung Woo
HW
Hong
Sung Hyun
SH
Lee
Yun-Sang
YS
Kil
Hee Sup
HS
Chi
Dae Yoon
DY
Lee
Dong Soo
DS
Chung
June-Key
JK
Lee
Myung Chul
MC
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D004355:Drug Stability; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005442:Flumazenil / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D007553:Isotope Labeling / Q000295:instrumentation* / Q000379:methods*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D051381:Rats; D011963:Receptors, GABA-A / Q000378:metabolism*
C483765:2'-fluoroflumazenil; D019275:Radiopharmaceuticals; D011963:Receptors, GABA-A; D005442:Flumazenil