Synthesis
To a 250 mL round bottom flask was added 16.5 g (100 mmol) of m-nitroacetophenone, 26.5 mL of N,N-dimethylformamide dimethyl acetal (200 mmol) and 100 mL of xylene. The reaction mixture was heated to 140 °C and kept for 12 hours. After completion of the reaction, the mixture was cooled to room temperature and the precipitate was collected by filtration. The precipitate was washed sequentially with petroleum ether and ethyl ether, and then purified by silica gel column chromatography (eluent: ethyl acetate/cyclohexane, 25/75, v/v) to afford 19.6 g of the yellow solid product, 3-(dimethylamino)-1-(3-nitrophenyl)prop-2-en-1-one, in 89% yield. The structure of the product was determined by 1H NMR (200 MHz, DMSO-d6) δ 8.59 (t, 1H), 8.42-8.23 (m, 1H), 7.81 (d, J = 12.1 Hz, 1H), 7.70 (t, J = 7.9 Hz, 1H), 5.89 (d, J = 12.1 Hz, 1H), 3.17 (s, 1H), 2.95 (s , 1H) and confirmed by 13C NMR (50 MHz, DMSO-d6) δ 182.8, 155.2, 147.9, 141.6, 133.4, 129.8, 125.1, 121.5, 90.3, 44.7, 37.3.
References
[1] Bioorganic and Medicinal Chemistry Letters, 2017, vol. 27, # 8, p. 1780 - 1783
[2] Patent: US2007/219183, 2007, A1. Location in patent: Page/Page column 11
[3] Bioorganic and Medicinal Chemistry Letters, 2009, vol. 19, # 10, p. 2735 - 2738
[4] Bioorganic and Medicinal Chemistry Letters, 2009, vol. 19, # 24, p. 6890 - 6892
[5] Patent: US2006/63784, 2006, A1. Location in patent: Page/Page column 43
