ABSTRACT
[carboxyl-(14) C]Celivarone was synthesised from barium [(14) C]carbonate with overall radiochemical yields in the range 49-53%. The synthetic route involves [(14) C]carbonylation methodology, which both decreased the number of synthetic steps and increased the yields obtained from previous synthetic routes.
Subject(s)
Anti-Arrhythmia Agents/chemical synthesis , Benzofurans/chemical synthesis , Carbon Monoxide/chemical synthesis , Carbon Radioisotopes/chemistry , Radiopharmaceuticals/chemical synthesis , Barium , Carbonates/chemical synthesis , Isotope Labeling/methodsABSTRACT
Aryl(alkynyl)iodonium salts have been demonstrated to be valuable precursors to a diverse range of heteroaromatic ring systems including aryl[1,2-a]imidazopyridines. Successful application, using the recently described aryl(alkynyl)iodonium trifluoroacetate salts, is described, highlighting for the first time that the regioselectivity of this process is both counter-ion and concentration dependent. Studies with a carbon-13 labelled substrate established that the reactions of alkynyliodonium salts are highly complex and that multiple mechanistic processes appear to be underway simultaneously.
ABSTRACT
A new approach to benzyne precursors has been developed that involves the [4+2] cycloaddition of trimethylsilyl alkynylboronates with 2-pyrones, followed by oxidation and trifluoromethylsulfonylation of the boronate moiety.
Subject(s)
Benzene Derivatives/chemistry , Boronic Acids/chemistry , Cyclization , Oxidation-Reduction , Pyrones/chemistryABSTRACT
A method for the parallel solid-phase synthesis (SPS) of iodinated analogues of Sanofi-Aventis' type 1 cannabinoid (CB1) receptor inverse agonist rimonabant (acomplia) has been developed. The method allows the synthesis of a range of C3 amide/hydrazide derivatives from a resin-bound C3 ester precursor. The C-Ge linkage to the Hypogel-200 resin is stable to the diversification conditions but allows ipso-iododegermylative cleavage using NaI/NCS even for the products containing the oxidatively labile hydrazide moiety.
Subject(s)
Drug Inverse Agonism , Halogenation , Piperidines/chemical synthesis , Piperidines/pharmacology , Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Receptor, Cannabinoid, CB1/agonists , Piperidines/chemistry , Pyrazoles/chemistry , Rimonabant , Structure-Activity RelationshipABSTRACT
Syntheses of two 4-phenylpiperidines from bromobenzene have been developed involving anchoring to a fluorous-tag, Ir-catalysed borylation, Pd- and Co-catalysed elaboration then traceless cleavage. Although performed using 'cold' (i.e. unlabelled) bromobenzene as the starting material, these routes have been designed to minimise material loss via volatile intermediates and expedite purification during radiosynthesis from 'hot' (i.e. [(14)C] labelled) bromobenzene.
Subject(s)
Boron/chemistry , Bromobenzenes/chemistry , Iridium/chemistry , Piperidines/chemistry , Catalysis , Isotopes , Radiochemistry , VolatilizationABSTRACT
Two radioligands, [(11)C] SR149080 and its morpholino analog [(11)C] SR149568, were synthesized by reaction of the respective phenolic precursors with [(11)C] methyl iodide. Both radioligands had appropriate regional brain distribution for cannabinoid receptors in mice with peak target to non-target ratios of 2.2 for [(11)C] SR149080 and 1.6 for [(11)C] SR149568 at 90 and 30 minutes post-injection respectively. The uptake of both tracers was blocked with a 1 mg/kg dose of SR141716A.