[2′-18F]-2-oxoquazepam: Synthesis of a 5-(2-[18F]fluorophenyl)-1,4-benzodiazepine-2-one
✍ Scribed by Peter Johnströma; Sharon Stone-Elander; Tim Duelfer
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- French
- Weight
- 545 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0022-2135
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The use of a 2‐amino‐2′‐[^18^F]fluorobenzhydrol as a radiolabelling intermediate in the synthesis of a 1,4‐benzodiazepine‐2‐one is demonstrated. 5‐Chloro‐2′‐[^18^F]fluoro‐2‐(N‐(2,2,2‐trifluoroethyl)amino)benzhydrol, 2, was synthesized by the coupling of the anilinodichloroborane reagent with 2‐[^18^F]fluorobenzaldehyde, 1 and was subsequently oxidized to the benzophenone, 3, using Jones reagent in 70–80% conversions after 10 min at 0–5°C. After solid phase extraction, 3 reacted with bromoacetyl bromide to generate the bromoamide, 4, in 90–95% conversions after 10 min at 140°C. Ring closure of 4 to the 1,4‐benzodiazepine‐2‐one, 5, was accomplished using hexamethylenetetramine in aqueous dimethylsulfoxide. Conversions of 80–90% were obtained after 10 min at 100°C. Following preliminary cleaning by solid phase extraction, 5 was isolated by radio‐HPLC. The total time of synthesis was 180–190 min and the isolated yield was on the order of 107ndash;12% (decay‐corrected) or 3–4% (not decay‐corrected) and based on [^18^F]F^−^. The radiochemical purity of the isolated 1,4‐benzodiazepine‐2‐one was >99% and the specific activity was ∼2000 Ci/mmol at the end‐of‐synthesis.
📜 SIMILAR VOLUMES
## Abstract A method for synthesizing ^18^F‐labelled 2‐amino‐2′‐fluorobenzhydrols under nocarrier‐added conditions for use as radiolabelled intermediates in the synthesis of[2′‐^18^F]‐1,4‐benzodiazepine‐2‐ones is presented. Anilinodichloroborane reagents were formed by the reaction of boron trichlo
## Abstract 2‐Oxoquazepam, 7‐chloro‐1‐(2,2,2‐trifluoroethyl)‐1,3‐dihydro‐5‐(2‐fluorophenyl)‐2H‐1,4‐benzo‐diazepine‐2‐one, is a benzodiazepine agonist. It has been shown to bind __in vitro__ with a higher affinity to benzodiazepine type 1 receptors than to type 2 receptors. Here we report the synthe
## Abstract The synthesis of 2‐([4‐^18^F]fluorophenyl)benzimidazole, which has potential to be used as a building block for many endogenous and pharmaceutical compounds, is reported. A range of solvents and catalysts as well as conventional and microwave heating have been investigated to optimise t
## Abstract Synthesis of 2′‐deoxy‐2′‐[^18^F]fluoro‐5‐methyl‐1‐__β__‐D‐arabinofuranosyluracil ([^18^F]‐FMAU) is reported. 2‐Deoxy‐2‐[^18^F]fluoro‐1,3,5‐tri‐O‐benzoyl‐__α__‐D‐arabinofuranose **2** was prepared by the reaction of the respective triflate **1** with tetrabutylammonium[^18^F]fluoride. Th
2-exo-(2 0 -Fluoro-3 0 -(4-fluorophenyl)-pyridin-5 0 -yl)-7-azabicyclo[2.2.1]heptane (F 2 PhEP), a novel, epibatidine-based, a4b2-selective nicotinic acetylcholine receptor antagonist of low toxicity, as well as the corresponding N-Boc-protected chloro-and bromo derivatives as precursors for labelli