Synthesis
GENERAL STEPS: A mixture of MgCl (930 mg, 9.8 mmol), triethylamine (TEA, 4.7 mL, 33.4 mmol), and dimethyl malonate (1.9 mL, 16.6 mmol) was stirred at room temperature for 1.5 hours. Subsequently, a toluene solution of 3-fluoro-4-nitrobenzoyl chloride was slowly added to the reaction system. The resulting mixture was continued to be stirred at room temperature for 15 h. Then 4 M HCl solution (4 mL) was added and stirred for 5 min. The reaction mixture was extracted with ethyl acetate (EtOAc, 30 mL x 3), the organic phases were combined and dried with anhydrous sodium sulfate (NaSO), filtered and concentrated under reduced pressure. To the concentrated residue was added 6 M HCl solution (30 mL) and the mixture was refluxed overnight. After cooling, the mixture was extracted with ethyl acetate (EtOAc, 30 mL x 3), the organic phase was dried over anhydrous sodium sulfate (NaSO), filtered and concentrated under reduced pressure. The crude product was purified by fast column chromatography (silica gel, gradient elution with ethyl acetate/hexane) to afford 1-(3-fluoro-4-nitrophenyl)ethanone (compound 3) as a light yellow solid (1.9 g, 63% yield).
References
[1] Patent: WO2016/145092, 2016, A1. Location in patent: Paragraph 0077; 0078; 0079; 0088; 0091; 0093; 0094
[2] Patent: WO2017/87428, 2017, A1. Location in patent: Paragraph 0061-0063
