Improved Syntheses of Precursors for PET Radioligands [F]XTRA and [F]AZAN.
Improved syntheses of 7-methyl-2-exo-[3'-(2-bromopyridin-3-yl)-5'-pyridinyl]-7-azabicyclo[2.2.1]heptanes (3) and 7-methyl-2-exo-[3'-(6-bromopyridin-2-yl)-5'-pyridinyl]-7-azabicyclo[2.2.1]heptanes (4), precursors for PET radioligands [(18)F]XTRA (1) and [(18)F]AZAN (2), involving a key Stille coupling step followed by deprotection of Boc group and N-methylation are described. The new synthetic procedures provided the title compounds in more than 40% overall yields.
Gao
Yongjun
Y
Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, 600 North Wolfe Street, Baltimore, Maryland 21287-0816.
Wang
Haofan
H
Mease
Ronnie C
RC
Pomper
Martin G
MG
Horti
Andrew G
AG