反应详情

1,2,3,4-Tetrahydro[1]benzofuro[2,3-c]pyridine was prepared by the method described by Jaen, J. and Wise, L. D.; J. Heterocycl. Chem. 1987, 1317-1319. To a reaction mixture containing Mg turnings (0.85, 35.41 mmol), a pinch of iodine in THF (5 mL) under N2 atmosphere was added a mixture of 2-bromoanisole (5.0 g, 26.7 mmol) and 1,2-dibromoethane (1.4 g, 8.8 mmol) in (10 mL) THF. When all the magnesium was consumed, a solution of 1-benzyl-4-piperidone (5.0 g, 28.24 mmol) in THF (10 mL) was added dropwise. Following the addition, the solution was refluxed for 20 minutes, and then stirred at room temperature for 2 h. The reaction mixture cooled to 0° C. and 10% HCl was added dropwise until the pH of the mixture was 1-2. The pH was adjusted to 10 with 2N NaOH and extracted with ether (2×100 mL). The organic extracts were dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure to furnish 1-benzyl-4-(2-methoxyphenyl)piperidin-4-ol (4.5 g, 90%). 1H NMR (200 MHz, CDCl3): δ 2.20 (d, J=17 Hz, 2H), 2.60-3.15 (m, 2H), 3.20-3.50 (m, 4H), 3.90 (s, 3H), 4.20 (d, J=7 Hz, 2H), 6.90-7.05 (m, 2H), 7.20-7.35 (m, 2H), 7.35-7.55 (m, 3H), 7.60-7.80 (m, 2H); m/e=297.

1. customWhen all the magnesium was consumed
2. additionthe addition
3. temperaturethe solution was refluxed for 20 minutes
4. temperatureThe reaction mixture cooled to 0° C.
5. extractionextracted with ether (2×100 mL)
6. dry with materialThe organic extracts were dried over anhydrous Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure