Description
5-Bromo-2-fluoropyridine is a halogenated pyridine that has been used as a molecular scaffold for many Active Pharmaceutical Ingredients (APIs) such as Neuropeptide Y Receptor Y5 Inhibitors, SARS-CoV-2 Major Protease Inhibitors, and Indoleamine-2,3-Dioxygenase-1 Inhibitors in cancer immunotherapy. 5-Bromo-2-fluoropyridine is also an ideal building block for semiconductors, due to its aromaticity and electron deficiency. A host material of 5-(5-(2,4,6-triiso-propylphenyl)pyridin-2-yl)-5H-benzo[d]benzo-[4,5]imidazo[1,2-a]imidazole is synthesized from 5-bromo-2-fluoropyridine for OLED applications.
Chemical Properties
5-Bromo-2-fluoropyridine is a colourless or yellowish liquid compound with a density of 1.71 g/cm3 at 25° C; boiling point of 162-164° C (lit.) at 750 mmHg; stored at room temperature.
Uses
5-Bromo-2-fluoropyridine is used in the synthesis of heteroaromatic and aniline derivatives of piperidines as potent ligands used for vesicular acetylcholine transport. Also used in the synthesis of benzofurano[3,2-d]pyrimidin-2-one derived inhbitors.
Synthesis
A. Synthesis of 2-fluoro-5-bromopyridine: 2.2 g (15.6 mmol) of 6-fluoronicotinic acid, 5.1 g of red mercuric oxide (HgO) and 1.2 ml of bromine were dissolved in 100 ml of carbon tetrachloride (CCl4) to form a suspension. The reaction was carried out under reflux conditions for 5 hours and subsequently cooled to room temperature. The reaction mixture was filtered through diatomaceous earth and the filtrate was concentrated under vacuum. The residue was dissolved in hexane, filtered again and the filtrate was concentrated under vacuum to give 1.73 g (63% yield) of 2-fluoro-5-bromopyridine, the product being a light yellow oil.
References
[1] Patent: US5618821, 1997, A
