Copper-Mediated Radiofluorination of Aryl Pinacolboronate Esters: A Straightforward Protocol by Using Pyridinium Sulfonates was written by Antuganov, Dmitrii;Zykov, Michail;Timofeev, Vasilii;Timofeeva, Ksenija;Antuganova, Yulija;Orlovskaya, Victoriya;Fedorova, Olga;Krasikova, Raisa. And the article was included in European Journal of Organic Chemistry in 2019.Application of 936902-12-4 This article mentions the following:
Radiofluorination of arylboronic acids pinacol esters (arylBPin) mediated by copper triflate pyridine complex is one of the more promising synthetic approaches for the direct introduction of nucleophilic [18F]fluoride into non-activated arenes and heteroarenes. However, the application of this method to the production of positron emission tomog. (PET) radiotracers in automated synthesizers remains a challenging task. The choice of phase-transfer catalyst (PTC) and corresponding base used for the generation of reactive [18F]fluoride species has a profound impact on the efficiency of the 18F-fluorination process. Herein the authors report the development of a simple procedure involving trapping of the aqueous [18F]fluoride on a weak anion-exchange resin (WAX) and its release by elution with pyridinium sulfonate in di-Me acetamide. Obtained reactive [18F]fluoride was used as-is in a copper-catalyzed fluorination reaction employing pyridinium salt as both PTC and base. High radiochem. conversion rates (RCCs) achieved for a series of simple arylBPin substrates and 4-[18F]fluoro-D,L-phenylalanine demonstrate the efficiency of this novel 18F-processing approach. Notably, the proposed method obviates conventional azeotropic drying steps, solvents evaporation and/or changeover and can be implemented on com. automated synthesizers. In the experiment, the researchers used many compounds, for example, 5-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[d]oxazole (cas: 936902-12-4Application of 936902-12-4).
5-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[d]oxazole (cas: 936902-12-4) belongs to benzoxazole derivatives. Benzoxazole derivatives have gained a lot of importance in the past few years because of their use in intermediates for the preparation of new biological materials. A number of marketed drugs are available having benzoxazole as core active moiety like, nonsteroidal anti-inflammatory drug (NSAID)—flunoxaprofen, benoxaprofen, antibiotic—calcimycin.Application of 936902-12-4
Referemce:
Benzoxazole – Wikipedia,
Benzoxazole | C7H5NO – PubChem