Journal of Labelled Compounds and Radiopharmaceuticals

Wilson, Hanna

doi: 10.1002/jlcr.691pmid: N/A

2,3,5,6‐Tetrafluorophenyl 2‐(2‐nitroimidazol‐1‐yl) acetate has been synthesized via an improved route which involves the direct coupling of 2‐(2‐nitroimidazol‐1‐yl) acetic acid with 2,3,5,6‐tetrafluorophenol. Copyright © 2003 John Wiley & Sons, Ltd.

Coumbarides, Gregory S.; Eames, Jason; Weerasooriya, Neluka

doi: 10.1002/jlcr.693pmid: N/A

A series of multi‐labelled aromatic ketones were efficiently synthesized using a deprotonation–deuteriation/alkylation strategy. The yields were high and the products are synthetically useful. Copyright © 2003 John Wiley & Sons, Ltd.

Gibson, Jennifer S.; Herbert, John M.

doi: 10.1002/jlcr.694pmid: N/A

Exposure of captodative enone systems to deuterium in the presence of Crabtree's catalyst (1) results in deuteration at the vinylic site β‐ to the ketone carbonyl, as well as at any accessible ortho‐position. β‐exchange is also observed during the reduction of ethyl cinnamate (3) catalyzed by 1. Copyright © 2003 John Wiley & Sons, Ltd.

Kuhnast, Bertrand; Bodenstein, Claudia; Wester, Hans Jürgen; Weber, Wolfang

doi: 10.1002/jlcr.695pmid: N/A

Matrix metalloproteinases (MMPs) are a family of proteinases that play an important role in cancer. Non invasive imaging of MMPs would allow the evaluation of MMP activity in cancer and the assessment of the response of MMP inhibitor based therapies. In this paper, we investigated the synthesis and labelling by methylation with (11C)CH3I of an N‐sulfonylamino acid derivative, the (2R)‐3‐methyl‐2‐((4‐((4‐methoxybenzoyl)amino)benzenesulfonyl)amino) butanoic acid, a selective and high potent MMP‐2 and MMP‐9 inhibitor, for cancer imaging with positron emission tomography. Labelling of (2R)‐3‐methyl‐2‐((4‐((4‐hydroxybenzoyl)amino)benzenesulfonyl) amino) butanoic acid was carried out in a radiochemical yield of 50%–60% within 40 min with a specific activity of 11–26 GBq/µmol (EOS). In vitro inhibitory activity studies, biodistribution and in vivo serum stability in normal mice are also described. Copyright © 2003 John Wiley & Sons, Ltd.

Iwata, Ren; Furumoto, Shozo; Pascali, Claudio; Bogni, Anna; Ishiwata, Kiichi

doi: 10.1002/jlcr.696pmid: N/A

Two positron‐emitting analogues of tyrosine, O‐(11C)methyl‐L‐tyrosine and O‐(18F)fluoromethyl‐L‐tyrosine were prepared as new tumor imaging agents. The alkylating agent, (11C)methyl triflate or (18F)fluoromethyl triflate, was simply bubbled through a dimethylsulfoxide solution of L‐tyrosine disodium salt at room temperature. After subsequent HPLC purification the labeled L‐tyrosine analogues were obtained in decay‐corrected radiochemical yields of over 50%, based on their corresponding labeling agent, with radiochemical purities always higher than 98%. The quite straightforward preparation, together with the high radiochemical yields achieved, make both these syntheses suitable for routine production. Copyright © 2003 John Wiley & Sons, Ltd.

Chappelle, Michael R.; Harding, John R.; Kent, Barry B.; Jones, John R.; Lu, Shui‐Yu; Morgan, Alan D.

doi: 10.1002/jlcr.697pmid: N/A

The development of combined microwave‐enhanced/parallel synthesis procedures and their application to the deuteriation of organic compounds via examples of solid‐state hydrogenation is reported. Other labelling procedures, such as solution state catalytic dehalogenations, hydrogenations as well as hydrogen isotope exchange reactions also benefit from the combined technology. Copyright © 2003 John Wiley & Sons, Ltd.

Bormans, G.; Cleynhens, B.; de Groot, T.J.; Mortelmans, L.; Moretti, J.‐L.; Verbruggen, A.

doi: 10.1002/jlcr.698pmid: N/A

S,S′‐bis‐trityl‐N‐BOC‐1,2‐ethylenedicysteamine (S,S′‐bis‐trityl‐N‐BOC–BAT) was conjugated to 2‐nitroimidazole (NIM) through a propylene spacer in order to provide a precursor for a potential technetium‐99 m labelled hypoxia tracer. For labelling with technetium‐99 m, a two‐step one‐pot procedure was developed consisting of deprotection of the ligand by heating in mild acidic conditions and subsequent exchange labelling in the presence of SnCl2, tartrate and 99mTcO −4. The labelling reaction mixture was analyzed using electrospray radio‐LC–MS and the observed mass spectrum corresponding to the main radiometric peak was in accordance with the predicted structure of oxo–Tc(V)–NIM–BAT. 99mTc–NIM–BAT was purified using RP–HPLC and its biodistribution was evaluated in normal mice at 10 min and 4 h p.i. 99mTc–NIM–BAT was cleared from plasma mainly by hepatobiliary excretion. Copyright © 2003 John Wiley & Sons, Ltd.

Zhang, Ming‐Rong; Furutsuka, Kenji; Yoshida, Yuichiro; Suzuki, Kazutoshi

doi: 10.1002/jlcr.703pmid: N/A

(18F)Fluoroethyl bromide ((18F)FEtBr) is a useful synthetic precursor to synthesize 18F‐labeled compounds. However, the lower reactivity of (18F)FEtBr with amine, phenol and amide functional groups than that of (11C)CH3I partly limits its wide application in the synthesis of (18F)fluoroethylated compounds. The aim of this study was to increase the reactivity of (18F)FEtBr with various nucleophilic substrates for PET tracers containing amine, phenol and amide moieties. The present strategies included (1) adding NaI into the reaction mixture of (18F)FEtBr and substrate, where (18F)FEtI is reversibly formed and becomes more reactive; (2) converting (18F)FEtBr into much more reactive (18F)FEtOTf, similar to conversion of (11C)CH3I into (11C)CH3OTf. By these efforts, the (18F)fluoroethylation efficiency of various substrates containing amine, phenol and amide groups with (18F)FEtBr/NaI and (18F)FEtOTf was significantly improved, compared with the corresponding reaction efficiency with (18F)FEtBr. Copyright © 2003 John Wiley & Sons, Ltd.