反应详情

107 ml of 1,2-dimethoxyethane were aerated with argon, and 597 mg (0.51 mmol) of Pd(PPh3)4 and 2.24 g (10.3 mmol) of methyl 3-brompyrazine-2-carboxylate were added. After 10 min, 3.9 g (15.45 mmol) of 2-(tert-butoxycarbonylaminomethyl)-phenylboronic acid and finally 10.7 ml of a 2M sodium carbonate solution were added. The mixture was heated to reflux for 18 h under argon, diluted with dichloromethane after cooling and washed with water. The organic phase was dried, concentrated and purified by chromatography on silica gel. 661 mg (19%) of a viscous oil were obtained. MS (ES+): m/z=344 (M+1), 288 (M−55). 1H-NMR (CDCl3): δ=8.78 (1H, d, J=2.4 Hz), 8.67 (1H, d, J=2.4 Hz), 7.54-7.14 (4H, m), 5.11 (1H, br s), 4.22 (2H, d, J=5.9 Hz), 3.79 (3H, s), 1.38 (9H, s).

1. additionwere added
2. temperatureThe mixture was heated
3. temperatureto reflux for 18 h under argon
4. temperatureafter cooling
5. washwashed with water
6. customThe organic phase was dried
7. concentrationconcentrated
8. custompurified by chromatography on silica gel