[Synthesis]
To a solution of N,N-dimethylacetamide (DMA, 10 ml) of 2-chloro-4-hydroxypyridine (1 g, 7.75 mmol) was sequentially added bromocyclopropane (2.8 g, 23.2 mmol), sodium iodide (1.16 g, 7.75 mmol) and cesium carbonate (5 g, 15.5 mmol). The reaction mixture was stirred in a microwave reactor at 170 °C for 20 min, followed by warming up to 180 °C and continued stirring for 30 min. After completion of the reaction, the reaction mixture was extracted with ethyl acetate (EA). The organic layers were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting crude product was purified by fast column chromatography to give 300 mg of 2-chloro-4-cyclopropoxypyridine. The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δ= 8.19 (d, J = 5.8 Hz, 1H), 7.02 (d, J = 2.0 Hz, 1H), 6.87 (dd, J = 2.0,5.8 Hz, 1H), 3.80 (tt, J = 3.0,6.0 Hz, 1H), 0.91-0.75 (m, 4H) . |
[References]
[1] Patent: WO2014/114185, 2014, A1. Location in patent: Page/Page column 162
[2] Patent: US2014/206681, 2014, A1. Location in patent: Paragraph 0889; 0890
[3] Patent: WO2014/113932, 2014, A1. Location in patent: Page/Page column 119 |