Synthesis of 11C-Labelled Haloalkanonitriles and Examples of their Use in Some Alkylation Reactions.

Hörnfeldt, Katarina; Antoni, Gunnar; Långström, Bengt; Uggerud, Einar; Ebbesen, Peter; Carcanague, Daniel R.; Chao, Ito; Houk, K. N.

doi:10.3891/acta.chem.scand.46-0087

Cited by 12 publications

(1 citation statement)

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“…EI/FAB-MS: 70 eV, Finnigan MAT 311 A. Elemental analysis: CHN-O-Rapid, Institut für Anorganische und Angewandte Chemie, Universität Hamburg (the elemental analyses of the cationic products 3 BF 4 are often hampered by the inclusion of varying amounts of CH 2 Cl 2 , as indicated by 1 H NMR spectra). [(η 5 -Cp)Fe(η 6 -Cot)]PF 6 ( 1 PF 6 ), CH(CO 2 Et) 2 (CH 2 ) 2 CO 2 Et, CH(CO 2 Me) 2 (CH 2 ) 3 CO 2 Et, CH(CO 2 Me) 2 (CH 2 ) 2 CN, and the sodium salts of the malonester derivatives were synthesized as described. HBF 4 was purchased as a 54% solution in diethyl ether from Fluka.…”

Section: Methodsmentioning

confidence: 99%

From Coordinated Cyclooctatetraene to cis-5,7-Disubstituted Cycloocta-1,3-diene by Iteratively Applied Nucleophilic and Electrophilic Addition

Reimelt

Heck

2003

Organometallics

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The addition of various carbanionic nucleophiles Nu1 to the cationic complex [(η5-Cp)Fe(η6-Cot)]+ (1) exclusively yields the neutral complex [(η5-Cp)Fe(1,2,3,4,5-η-C8H8Nu1)] (2) with Nu1 in exo position with respect to the metal center: Nu1 = CH(CO2Me)2 (2a), CEt(CO2Me)2 (2b), CPh2CN (2c), CH(CN)2 (2d), C(CO2Et)2(CH2)2CO2Et (2e), C(CO2Et)2(CH2)3CO2Et (2f), C(CO2Me)2(CH2)2CN (2g), CH(COMe)CO2Et (2h). Protonation of 2 by HBF4 reveals the complexes [(η5-Cp)Fe(η6-C8H9Nu1)]BF4 (3BF4) with a 1,2,3,4,5,6-η coordination mode of the cyclo-C8 ligand. The cationic complexes 3 are suitable for a second nucleophilic addition affording the exo-6,8-disubstituted cyclooctadienyl complex [(η5-Cp)Fe(1,2,3,4,5-η-C8H9-6-Nu1-8-Nu2)] (4): Nu1/Nu2 = CH(CO2Me)2/CH(CO2Me)2 (4a), CEt(CO2Me)2/CH(CO2Me)2 (4b), CPh2CN/CPh2CN (4c). It can be shown that the nucleophilic addition occurs not only with the carbanionic nucleophiles, which must be prepared separately by deprotonation reactions with NaH, but also in-situ, when the cationic complex, the C,H acidic substrate, and the strong base tetramethyl guanidine (TMG) are present. The capability of facile deprotonation reaction by TMG enables a one-pot procedure of the synthesis of 4a without isolation of the intermediates 2 and 3. Attempts of intramolecular nucleophilic additions in 3dBF4 (Nu1 = C(CO2Et)2(CH2)2CO2Et) and 3eBF4 (Nu1 = C(CO2Et)2(CH2)3CO2Et) by application of TMG failed in the formation of cyclo-C8-based bicycles but rather result in addition of TMG to the cyclo-C8 ligand forming 4d and 4e with tetramethyl guanidinyl as Nu2. The protonation of 4a−c in acetonitrile by addition of CF3CO2H splits off the cyclo-C8 ligand as a cis-5,7-disubstituted cycloocta-1,3-diene (6): Nu1/Nu2 = CH(CO2Me)2/CH(CO2Me)2 (6a), CEt(CO2Me)2/CH(CO2Me)2 (6b), CPh2CN/CPh2CN (6c). The protonation of 4d and 4e cleaves the guanidinyl substituent and recovers the starting complexes 3d and 3e. When the steric demand of Nu1 and Nu2 is different, as in 4b, the isomer that bears the sterically most demanding nucleophile proximal to the endocyclic carbon−carbon double bond is preferentially formed.

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Section: Methodsmentioning

confidence: 99%

From Coordinated Cyclooctatetraene to cis-5,7-Disubstituted Cycloocta-1,3-diene by Iteratively Applied Nucleophilic and Electrophilic Addition

Reimelt

Heck

2003

Organometallics

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[Tetrazoyl-11C]LY202157 synthesis forin vivo studies of the NMDA receptor channel complex

Ponchant

Galéa

Bottlaender

et al. 2000

J. Labelled Cpd. Radiopharm.

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[Tetrazoyl‐11C]LY202157 8 was prepared via a three step synthesis from ethyl (3S,4aR,6S,8aR)‐6‐bromomethyl‐2‐methoxycarbonyl‐1,2,3,4,4a,5,6,7,8,8a‐decahydroisoquinoline‐3‐carboxylate 4. This bromo precursor was reacted with [11C]hydrogen cyanide affording the corresponding [11C]nitrile. Conversion to the tetrazole was achieved by treatment with azidotributyltin followed by hydrolysis with 6N hydrochloric acid at 200°C. After HPLC purification and analytical HPLC control, more than 370 MBq (10 mCi) of [tetrazoyl‐11C] LY202157 were obtained after an overall 60 minute synthesis time with 38% yield (EOB) and specific activity of 25.9 GBq/µmol (700 mCi/µmol). Ex vivo biological studies showed that the [tetrazoyl‐11C] LY202157 did not cross the brain blood barrier. Copyright © 2000 John Wiley & Sons, Ltd.

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Preparation of [¹¹C]diethyl oxalate and [¹¹C]oxalic acid and demonstration of their use in the synthesis of [¹¹C]‐2,3‐dihydroxyquinoxaline

Thorell¹,

Stone‐Elander²,

Elander³

1993

Labelled Comp Radiopharmac

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HC1 in ethanol generated 2, which could subsequently be converted to 3 with aqueous acid. The total time of preparation from end-of-trapping of [llC]cyanide was 6-7 min using combined microwave and thermal treatment or, by exclusively thermal treatment, 15 and 20 min for 2 and 3, respectively. The radiochemical conversion of ["Clcyanide to 2 and 3 was -80% and -708, respectively. Both 2 and 3 were used in a model reaction with 1,2-phenylenediamine to synthesize the heterocyclic compound, 2,3-dihydroxyquinoxaline, a basic structural unit in antagonists for the excitatory amino acid receptor system.

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Synthesis of 11C-Labelled Haloalkanonitriles and Examples of their Use in Some Alkylation Reactions.

Cited by 12 publications

References 0 publications

From Coordinated Cyclooctatetraene to cis-5,7-Disubstituted Cycloocta-1,3-diene by Iteratively Applied Nucleophilic and Electrophilic Addition

From Coordinated Cyclooctatetraene to cis-5,7-Disubstituted Cycloocta-1,3-diene by Iteratively Applied Nucleophilic and Electrophilic Addition

[Tetrazoyl-11C]LY202157 synthesis forin vivo studies of the NMDA receptor channel complex

Preparation of [¹¹C]diethyl oxalate and [¹¹C]oxalic acid and demonstration of their use in the synthesis of [¹¹C]‐2,3‐dihydroxyquinoxaline

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Synthesis of 11C-Labelled Haloalkanonitriles and Examples of their Use in Some Alkylation Reactions.

Cited by 12 publications

References 0 publications

From Coordinated Cyclooctatetraene to cis-5,7-Disubstituted Cycloocta-1,3-diene by Iteratively Applied Nucleophilic and Electrophilic Addition

From Coordinated Cyclooctatetraene to cis-5,7-Disubstituted Cycloocta-1,3-diene by Iteratively Applied Nucleophilic and Electrophilic Addition

[Tetrazoyl-11C]LY202157 synthesis forin vivo studies of the NMDA receptor channel complex

Preparation of [11C]diethyl oxalate and [11C]oxalic acid and demonstration of their use in the synthesis of [11C]‐2,3‐dihydroxyquinoxaline

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Preparation of [¹¹C]diethyl oxalate and [¹¹C]oxalic acid and demonstration of their use in the synthesis of [¹¹C]‐2,3‐dihydroxyquinoxaline