Fully automated [18F] fluorocholine synthesis in the TracerLab MxFDG Coincidence Synthesizer

articl

In vivo quantification of 5-HT1A-[F-18] MPPF interactions in rats using the YAP-(S) PET scanner and a beta-microprobe

We performed full modeling analysis of 5-HT1A-[F-18] MPPF interactions using the beta-microprobe (beta P) and a YAP-(S) PET scanner. Sixteen Wistar rats were used for beta P (n= 5) and YAP-(S) PET (n= 5) acquisitions and metabolite studies (n= 6). Time -concentration curves were obtained in the hippocampus, raphe dorsalis, frontal cortex and cerebellum, using three injections of [ 18F] MPPF at different specific activities. B'(max) values were estimated from a two (2T-5k)-and three (3T-7k)-tissue-compartment model with beta P and YAP-(S) PET time concentration curves. The simplified reference tissue model (SRTM) was used to estimate binding potential (BPSRTM) values from data obtained with the first injection and the cerebellum as the reference region. Overall, the 3T-7k model provided a better fit than the 2T-5k model, as evaluated from AIC criteria in all experiments. The rank order of receptor density (B'(max)) values was as follows: hippocampus > raphe approximate to frontal cortex > cerebellum. Non-negligible specific binding was observed in the cerebellum (B'(max) (beta P)= 1.5 +/- 0.9 pmol/ ml). Significant correlations (pb0.001) between B'(max) and BPSRTM values were evident with both beta P (r= 0.895) and YAP-(S) PET (r= 0.695). The YAP-(S) PET system underestimated the [ 18F] MPPF binding levels in brain due to limited resolution (i. e. partial volume), but led to similar conclusions. (C) 2008 Elsevier Inc. All rights reserved

Triphosgene–Amine Base Promoted Chlorination of Unactivated Aliphatic Alcohols

Unactivated α-branched primary and secondary aliphatic alcohols have been successfully transformed into their corresponding alkyl chlorides in high yields upon treatment with a mixture of triphosgene and pyridine in dichloromethane at reflux. These mild chlorination conditions are high yielding, stereospecific, and well tolerated by numerous sensitive functionalities. Furthermore, no nuisance waste products are generated in the course of the reactions. [Image: see text

Improved simplicity and practicability in copper-catalyzed alkynylation of tetrahydroisoquinoline

Alkynylation reactions of N-protected tetrahydroisoquinolines have been performed using several different protocols of cross dehydrogenative coupling. Initially, a CuCl-catalyzed method was investigated, which worked well with three different N-protecting groups, namely phenyl, PMP, and benzyl and t-BuOOH as oxidant in acetonitrile as solvent. The peroxide could then be replaced by simple air and acetonitrile for water, leading to an overall very environmentally friendly protocol. Finally, a decarboxylative alkynylation protocol starting from alkynoic acids was also developed using again air as oxidant. This avoids the use of gaseous alkynes in the introduction of short-chained alkyne substituents.Austrian Science Foundation (FWF)911041