Synthesis
c) 5-fluoro-2-methoxy-3-nitropyridine (Preparation 5b, 0.300 g, 1.74 mmol) was used as a raw material, which was dissolved in ethanol and 10% palladium carbon catalyst (0.300 g) was added. The reaction mixture was stirred at room temperature and under hydrogen atmosphere. after 5 h, the reaction was completed and the catalyst was removed by Celite filtration. The filter cake was washed with ethanol and the filtrate and washings were combined and concentrated to afford the target product 5-fluoro-2-methoxypyridin-3-amine (0.220 g, 89% yield) as a brown solid. Low resolution mass spectrometry (LRMS) showed m/z: 143 (M+1)+. 1H NMR (300 MHz, CDCl3) data: δ 3.96 (s, 3H), 6.67 (dd, 1H), 7.39 (d, 1H).
References
[1] Patent: EP2527344, 2012, A1. Location in patent: Page/Page column 22-23
[2] Patent: WO2012/160030, 2012, A1. Location in patent: Page/Page column 67
[3] Patent: WO2016/106331, 2016, A1. Location in patent: Paragraph 0201
