[Synthesis]
To a solution of 2-bromo-6-methylpyridine (5.00 g, 29.0 mmol, CAS 5315-25-3) in tetrahydrofuran (THF, 100 mL) was slowly added lithium diisopropylammonium (LDA, 2.0 M, 30.5 mL) at -70 °C. The reaction temperature was maintained at -70 °C and after stirring for 0.5 h, diethyl carbonate (5.26 mL, 43.6 mmol) was added. The reaction mixture was slowly warmed to 20 °C and stirring was continued at this temperature for 4 hours. Upon completion of the reaction, the reaction mixture was washed with deionized water (120 mL) and subsequently extracted with ethyl acetate (3 x 150 mL). The organic layers were combined, dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate=10:1, v/v) to afford ethyl (6-bromopyridin-2-yl)acetate (5.50 g, 77% yield) as a pale yellow oil.1H NMR (400 MHz, CDCl3) δ=7.50-7.41 (m, 1H), 7.33 (d, J=7.6 Hz, 1H ), 7.21 (d, J=7.6Hz, 1H), 4.11 (q, J=7.2Hz, 2H), 3.75 (s, 2H), 1.20 (t, J=7.2Hz, 3H). |
[References]
[1] Journal of Organic Chemistry, 2018, vol. 83, # 16, p. 9088 - 9095 [2] Patent: WO2018/106636, 2018, A1. Location in patent: Paragraph 00238 [3] Patent: US2016/297762, 2016, A1. Location in patent: Paragraph 0361-0362 |