Comparison of two synthetic methods to obtain [18F] N-(2-aminoethyl)-5-fluoropyridine-2-carboxamide, a potential MAO-B imaging tracer for PET
✍ Scribed by H.-F. Beer; M. Haeberli; S. Ametamey; P. A. Schubiger
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- French
- Weight
- 524 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0022-2135
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✦ Synopsis
Abstract
The compound Ro 19‐6327, N‐(2‐aminoethyl)‐5‐chloropyridine‐2‐carboxamide, is known to inhibit reversibly and site specifically the enzyme monoamine oxidase B (MAO‐B). The ^123^I‐labelled iodo‐analogue N‐(2‐aminoethyl)‐5‐iodopyridine‐2‐carboxamide (Ro 43‐0463) was investigated successfully in human volunteers by means of SPET (Single Photon Emission Tomography). We developed therefore the synthesis and radiolabelling of the corresponding fluoro‐analogue N‐(2‐aminoethyl)‐5‐fluoropyridine‐2‐carboxamide with ^18^F in order to carry out PET (Positron Emission Tomography) investigations of MAO‐B related neuropsychiatric diseases. For this purpose two synthetic approaches leading to the electrophilic and the nucleophilic methods of ^18^F radiolabelling were undertaken. The nucleophilic approach appeared to be superior when factors such as precursor synthesis, beam time, specific activity and radiochemical purity of the product are considered.