TY - JOUR
T1 - 3β-(p-trimethylsilylphenyl)tropane-2β-carboxylic acid methyl ester
T2 - A new precursor for the preparation of [123I]RTI-55
AU - Musachio, John L.
AU - Keverline, Kathryn I.
AU - Carroll, F. Ivy
AU - Dannals, Robert F.
N1 - Funding Information:
Acknowledgement--This work was supported by USPHS Grant NS-15080 and DA-05477.
PY - 1996/1
Y1 - 1996/1
N2 - Here we report the synthesis of 3β-(p-trimethylsilylphenyl)tropane-2β-carboxylic acid methyl ester, a new, easily prepared precursor for the synthesis of radioiodinated versions of RTI-55. In contrast to the 3β-(p-trimethylstannylated) precursor for radioiodination, the aryl silane is prepared directly by the 1,4 addition of p-trimethylsilylphenylmagnesium iodide to anhydroecgonine methyl ester in 49% yield (Scheme 1). Radioiododesilylation proceeded smoothly (approx. 85% radioincorporation after 15min at room temperature) using 1 μg of the novel precursor in trifluoroacetic acid and chloramine-T as oxidant. Isolated radiochemical yields for 125I and 123I radiolabelings were 72 and 48%, respectively, with a calculated specific activity for [123I]RTI-55 of > 2000 mCi/μmol.
AB - Here we report the synthesis of 3β-(p-trimethylsilylphenyl)tropane-2β-carboxylic acid methyl ester, a new, easily prepared precursor for the synthesis of radioiodinated versions of RTI-55. In contrast to the 3β-(p-trimethylstannylated) precursor for radioiodination, the aryl silane is prepared directly by the 1,4 addition of p-trimethylsilylphenylmagnesium iodide to anhydroecgonine methyl ester in 49% yield (Scheme 1). Radioiododesilylation proceeded smoothly (approx. 85% radioincorporation after 15min at room temperature) using 1 μg of the novel precursor in trifluoroacetic acid and chloramine-T as oxidant. Isolated radiochemical yields for 125I and 123I radiolabelings were 72 and 48%, respectively, with a calculated specific activity for [123I]RTI-55 of > 2000 mCi/μmol.
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U2 - 10.1016/0969-8043(95)00259-6
DO - 10.1016/0969-8043(95)00259-6
M3 - Article
C2 - 8589674
AN - SCOPUS:0030049644
SN - 0969-8043
VL - 47
SP - 79
EP - 81
JO - Applied Radiation and Isotopes
JF - Applied Radiation and Isotopes
IS - 1
ER -