Tetrahydrofuran → (5-Bromo-pyridin-3-yl)-cyclopropyl-methanol
Reaktionsgleichung
Br[C:2]1[CH:3]=[N:4][CH:5]=[C:6]([Br:8])[CH:7]=1.[Cl-].[Li+].C([Mg+])(C)C.[Cl-].[O:16]1[CH2:20][CH2:19][CH2:18][CH2:17]1>>[Br:8][C:6]1[CH:7]=[C:2]([CH:20]([CH:19]2[CH2:17][CH2:18]2)[OH:16])[CH:3]=[N:4][CH:5]=1Komponenten
4
Reaktionsbedingungen
- Temperatur
- 0 °C
Versuchsvorschrift
3,5-Dibromo-pyridine (1 g, 4.22 mmol) was dissolved in 5 mL of tetrahydrofuran and cooled to 0° C. A solution of isopropyl magnesium lithium chloride (15% in tetrahydrofuran, 5.07 mL, 5.06 mmol) was added dropwise and the solution was stirred for 15 min at 0° C. The resulting solution was added to a solution of cyclopropyl aldehyde (0.31 mL, 4.22 mmol) in 2 mL of tetrahydrofuran at 0° C. and the mixture was stirred for another 30 min at 0° C. The reaction was quenched with a saturated solution of ammonium chloride (10 mL) and water (10 mL). The crude mixture was passed through a Varian Chemelut cartridge (ethyl acetate as eluent) and concentrated to afford 623 mg of (5-Bromo-pyridin-3-yl)-cyclopropyl-methanol as an oil (2.73 mmol, 65% yield). 1H NMR (500 MHz, DMSO-d6) δ 8.57 (m, 2H), 7.99 (t, J=2 Hz, 1H), 5.49 (d, J=5 Hz, 1H), 4.02 (m, 1H), 1.04 (m, 1H), 0.47 (m, 1H), 0.4 (m, 3H). MS: m/z 228.0/230.0 (M+H+).