394-42-3

White solid

2-Fluoro-4-methoxybenzoic acid (2FMBA) is a potent antimicrobial agent that inhibits the growth of bacteria, fungi and other microorganisms. 2FMBA has significant antibacterial activity against Gram-positive and Gram-negative bacteria and also has significant antifungal activity against Candida albicans. 2FMBA is active in the presence of light and is a strong acid. It can be synthesized by refluxing benzoic acid with hydrazine, or by reacting an aromatic carboxylic acid with oxychloride. 2FMBA is used to treat bacterial infections such as E. coli, Staphylococcus, Salmonella, Shigella and Mycoplasma; fungal infections such as Candida albicans; and protozoal infections such as Giardia lamblia.

Step a) 2-fluoro-4-methoxybenzaldehyde (15 g, 97.4 mmol) was added to a mixture of silver oxide (Ag2O, 13.5 g, 58.4 mmol), sodium hydroxide (NaOH, 19.5 g, 487 mmol), and water (200 mL) preheated to 55 °C. The reaction mixture was stirred at 55 °C for 1 h. Subsequently, it was filtered and the precipitated solid was washed with hot water (10 mL). The filtrate was slowly added to 5N hydrochloric acid (HCl) pre-cooled to 0°C under vigorous stirring. The precipitated solid was filtered, washed with water and dried to give 2-fluoro-4-methoxybenzoic acid as a white solid (13.6 g, 82% yield, melting point 194-196°C); mass spectrum (MS) showed m/e 169 (M-H)+.

[1] Patent: US2003/199562, 2003, A1
[2] Patent: US2006/46968, 2006, A1. Location in patent: Page/Page column 28-29
[3] Journal of the Chemical Society, 1929, p. 1639
[4] RSC Advances, 2016, vol. 6, # 38, p. 32319 - 32327