反应详情

To a stirred solution of 2-amino-5-bromo-4-methylpyridine (10 g, 54 mmole) in propionitrile (50 mL) was added ethyl acrylate (17 mL, 157 mmole), DIEA (19 mL, 106 mmole), palladium(II) acetate (0.61 g, 2.7 mmole) and tri-o-tolylphosphine (1.64 g, 5.4 mmole). The reaction was purged with argon and heated at reflux for 6 hr, then was cooled to RT and concentrated to dryness under vacuum. The resulting residue was taken up in ethyl acetate and filtered through a pad of silica gel. The filtrate was concentrated and the remaining residue was triturated with 1:1 Et2O/petroleum ether (50 mL), filtered, and dried under vacuum to give the title compound (6.50 g, 59%) as a pale yellow solid: 1H NMR (400 MHz, DMSO-d6) δ 8.31 (s, 1 H), 7.66 (d, J=16.0 Hz, 1 H), 6.40 (br s, 2 H), 6.32 (d, J=16.0 Hz, 1 H), 6.28 (s, 1 H), 4.15 (q, 2 H), 2.24 (s, 3 H), 1.24 (t, 3 H).

1. customThe reaction was purged with argon
2. temperatureheated
3. temperatureat reflux for 6 hr
4. concentrationconcentrated to dryness under vacuum
5. filtrationfiltered through a pad of silica gel
6. concentrationThe filtrate was concentrated
7. customthe remaining residue was triturated with 1:1 Et2O/petroleum ether (50 mL)
8. filtrationfiltered
9. customdried under vacuum