18F fluoroethylations: different strategies for the rapid translation of 11C-methylated radiotracers

2-[18F]Fluoroethyl tosylate – a versatile tool for building18F-based radiotracers for positron emission tomography

“…An important step was the finding that by addition of alkali iodides, the yield of [ 18 F]fluoroethylation could be significantly increased 10 as well as the fact that the reactivity of [ 18 F]FETs could be further improved by introduction of strong electron-withdrawing substituents such as e.g. in 2-[ 18 19,20 Acknowledging that application of HPLC-purified [ 18 F]FETs had a significant impact on the labeling yield, chemical and radiochemical purity of the final radiotracer 13,44 has triggered the development of innovative automated methods for production and purification of [ 18 [28][29][30][31] and equally in the [ 18 F]fluoroethylation of other amino acids like methionine and tryptophan. 33,73,[104][105][106] In radiotracer building, the reaction with [ 18 F]FETs is indispensable as has been demonstrated for a multitude of Oand N-[ 18 F]fluoroethylations, the radiolabeling of thiols 106,107,109 and the formation of [ 18 F]fluoroethyl-carboxylic esters, [63][64][65][66]102 -amides 89 and -phosphorus esters.…”

“…To circumvent the latter drawback, intermediate purification steps for [ 18 F]FETs have been developed comprising solid phase extraction (SPE) as well as HPLCbased procedures, partly remote-controlled, which as a consequence, afford the implementation of a two-pot radiolabeling procedure. 12,13 This review will summarize the role of [ 18 F]FETs as a labeling block in PET radiochemistry, its usage in the synthesis of radiopharmaceuticals with clinical relevance like [ 18…”

Effects of bilateral sequential theta-burst stimulation on 5-HT1A receptors on dorsolateral prefrontal cortex in treatment resistant depression

“…All scans were acquired in 3-D mode for 90 minutes (51 frames: 12×5 s, 6×10 s, 3×20 s, 6×30 s, 9×60 s, 15×300 s) and were reconstructed (iterative filtered back-projection algorithm) to final images comprising a spatial resolution of 4.36mm full-width at half-maximum 1 cm next to the center of the field of view (matrix 128×128, 35 slices). The radioligand [ carbonyl -11C]WAY-100635 was prepared according to previously published methods [58] at the Cyclotron Unit of the PET Center. Each PET scan was complemented with arterial blood samples for the quantification of [ carbonyl - 11 C]WAY-100635 that were automatically drawn for first 10 minutes (ALLOGG, Mariefred, Sweden) and manually at 2, 5, 6, 7, 8, 10, 20, 40 and 60 minute of the measurement.…”

Automatisation and First Evaluation of [18F]FE@SUPPY:2, an Alternative PET-Tracer for the Adenosine A3 Receptor: A Comparison with [18F]FE@SUPPY

“…Hence, having developed a series of fluoroethyl-esters over the last five years [24][25][26][27][28][29], it was obvious for us to develop [ 18 F]FE@SUPPY:2. …”