[Br:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]([CH:8]=[O:9])[CH:3]=1.[CH2:10]1COCC1.C[Mg]Br>CCOCC>[Br:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]([CH:8]([OH:9])[CH3:10])[CH:3]=1An oven-dried flask was cooled under argon, and to it was added 4-bromopicolinaldehyde (2.98 g, 16 mmol) and anhydrous THF (50 mL). The mixture was cooled to −78° C., and 3M methylmagnesium bromide in Et2O (6.4 mL) was added dropwise. The mixture was then allowed to warm slowly to room temperature, whereupon it was quenched with saturated NH4Cl solution. The aqueous layer was extracted with EtOAc, dried over Na2SO4, concentrated, and purified by column chromatography (gradient 0 to 60% EtOAc in hexanes) to give the product. 1H NMR (400 MHz, CDCl3) δ 8.36 (d, J=5.3 Hz, 1H), 7.57-7.48 (m, 1H), 7.38 (dd, J=5.3, 1.4 Hz, 1H), 4.88 (q, J=6.6 Hz, 1H), 3.84 (br s, 1H), 1.51 (d, J=6.6 Hz, 3H).
Wird geladen…
