反应详情

6-Bromomethyl-pyridine-2-carboxylic acid ethyl ester (1:1.72 g, 48 mmol; from Step 1 above) was dissolved in acetone (250 mL) and 4-iodophenol (11.61 g, 52.8 mmol; available from Aldrich Chemical Company, Inc., Milwaukee, Wis.) was added, followed by potassium carbonate (7.55 g, 54.6 mmol). The mixture was heated overnight at 65 degrees, and it was then cooled and filtered. The solid was washed with small portions of acetone and the filtrate was concentrated to approximately 100 mL by evaporation. The solution was warmed and then diluted with water (approximately 70 mL). The resulting brown solution was cloudy and started to precipitate an oily solid. The mixture was scratched with a spatula and allowed to cool to room temperature. The off-white precipitate was filtered off, washed with several portions of acetone/water (1:1), and then dried in vacuo over phosphorus pentoxide to give 6-(4-iodo-phenoxymethyl)-pyridine-2-carboxylic acid ethyl ester (13.72 g, 75%) as an off-white crystalline solid. MS (MH+) 384. 1HNMR (CDCl3): δ 1.47 (t, 3H, J=7 Hz), 4.52 (q, 2H, J=7 Hz), 5.33 (s, 2H), 6.78 (d, 2H, J=9 Hz), 7.58 (d, 2H, J=9 Hz), 7.74 (d, 1H, J=7.8 Hz), 7.91 (dd, 1H, J=7.8, 7.8 Hz), 8.09 (d, 1H, J=7.8 Hz).

1. temperatureThe mixture was heated overnight at 65 degrees
2. temperatureit was then cooled
3. filtrationfiltered
4. washThe solid was washed with small portions of acetone
5. concentrationthe filtrate was concentrated to approximately 100 mL by evaporation
6. temperatureThe solution was warmed
7. additiondiluted with water (approximately 70 mL)
8. customto precipitate an oily solid
9. filtrationThe off-white precipitate was filtered off
10. washwashed with several portions of acetone/water (1:1)
11. dry with materialdried in vacuo over phosphorus pentoxide