反应详情

温度

-40 °C

(General Grignard addition reaction procedure): a mixture of 2-Chloro-4-(5-formyl-pyridin-3-yl)-benzonitrile (0.243 g, 1 mmol), titanium(IV) isopropoxide (0.586 mL, 2.000 mmol), ethanesulfonamide (0.109 g, 1.000 mmol) in Toluene (20 mL) was heated to reflux for 4 hr. After concentration, the residue was dissolved in THF (15 mL) and cooled to −40° C. A solution of isopropenylmagnesium bromide (1.500 mL, 3.000 mmol) was added dropwise and the resulting mixture was slowly warmed up to −20° C. and stirred at this temperature for 4 hr. After quenched by NH4Cl solution, filtration, extraction with CH2Cl2, the solution was dried over Na2SO4, and concentrated, the residue was purified by flash column (MeOH—CH2Cl2, v/v, 1%-3%) and yielded a yellow solid (90 mg). Enantiomers were separated by 40% EtOH 60% heptane on a Chiralpak IA column. First peak 14 min (enantiomer 1), second peak 20 min (enantiomer 2). ESI-MS m/z: 378.1 [M+H]+, 1H NMR (400 MHz, CDCl3): δ 0.93 (d, J=6.7 Hz, 3H), 1.06 (d, J=6.7 Hz, 3H), 1.21 (t, J=8.0 Hz, 3H), 2.04-2.11 (m, 1H), 2.76-2.91 (m, 2H), 4.36 (t, J=7.4 Hz, 1H), 4.90 (d, J=7.6 Hz, 1H), 7.58 (d, J=8.2 Hz, 1H), 7.72 (s, 1H), 7.77 (s, 1H), 7.78 (d, J=8.2 Hz, 1H), 8.61 (s, 1H), 8.77 (s, 1H).

1. addition(General Grignard addition reaction procedure)
2. temperaturewas heated
3. temperatureto reflux for 4 hr
4. concentrationAfter concentration
5. dissolutionthe residue was dissolved in THF (15 mL)
6. temperaturethe resulting mixture was slowly warmed up to −20° C.
7. customAfter quenched by NH4Cl solution, filtration, extraction with CH2Cl2
8. dry with materialthe solution was dried over Na2SO4
9. concentrationconcentrated
10. customthe residue was purified by flash column (MeOH—CH2Cl2, v/v, 1%-3%)