Synthesis
A solution of 1-(2-fluorophenyl)ethanone (90.0 g, 652 mmol) with fuming nitric acid (53.1 mL) in concentrated sulfuric acid (129 mL) was slowly added dropwise to concentrated sulfuric acid (360 mL, 93-98%) pre-cooled to -42 °C under mechanical stirring. The reaction mixture was kept stirred at -42°C for 30 minutes. Upon completion of the reaction, the mixture was slowly poured into ice (1.3 kg) to quench the reaction. Subsequently, water (1 L) was added to precipitate the product from the solution. After all the ice melted, the precipitate was collected by filtration. The resulting solid was dissolved in EtOAc and the organic layer was washed sequentially with 5% aqueous Na2CO3 (2 x 300 mL), water (1 x 300 mL) and brine (1 x 300 mL), dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated to give a yellow solid 1-(2-fluoro-5-nitrophenyl)ethanone (115 g, 97% yield).
References
[1] Patent: WO2012/139425, 2012, A1. Location in patent: Page/Page column 117
[2] Patent: WO2011/44184, 2011, A1. Location in patent: Page/Page column 99-100
[3] Patent: US2004/122237, 2004, A1. Location in patent: Page 388
[4] Journal of Heterocyclic Chemistry, 1991, vol. 28, # 3, p. 673 - 683
[5] Patent: US2002/151715, 2002, A1
