Synthesis
The general procedure for the synthesis of 2-nitro-5-fluorobenzonitrile from 5-fluoro-2-nitrobenzamide was as follows: dry DMF (70 mL) was cooled to -10 °C and thionyl chloride (6 mL, 82 mmol) was added slowly and dropwise over 10 min. Subsequently, 5-fluoro-2-nitrobenzoic acid (15.04 g, 82 mmol) was added in batches over 1 hour. After the reaction mixture was gradually warmed to room temperature, it was poured into water (200 mL). The precipitate formed was collected by filtration, washed with water and dried to afford the target product 2-nitro-5-fluorobenzonitrile as a colorless solid (10.7 g, 79% yield). The structure of the product was confirmed by 1H NMR (CDCl3): δ 8.41 (1H, m), 7.62 (1H, m), 7.52 (1H, m).
References
[1] Patent: WO2006/129120, 2006, A2. Location in patent: Page/Page column 78
[2] Patent: US2010/280268, 2010, A1. Location in patent: Page/Page column 46
