[CH2:1]([O:3][CH2:4][N:5]1[CH:9]=[CH:8][N:7]=[C:6]1[Sn](CCCC)(CCCC)CCCC)[CH3:2].Br[C:24]1[S:25][CH:26]=[CH:27][N:28]=1.C([O-])(O)=O.[Na+]>C1(C)C=CC=CC=1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH2:1]([O:3][CH2:4][N:5]1[CH:9]=[CH:8][N:7]=[C:6]1[C:24]1[S:25][CH:26]=[CH:27][N:28]=1)[CH3:2]
A solution of crude 1-ethoxymethyl-2-tributylstannanyl-1H-imidazole (previous example), 2-bromothiazole (1.05 mL, 11.6 mmol, 1.0 equivalents based on integration of 1H NMR of crude 1-ethoxymethyl-2-tributylstannanyl-1H-imidazole), and Pd(PPh3)4 (0.67 g, 0.58 mmol) in toluene (20 mL) is stirred at 80° C. for 18 hours. After cooling to room temperature, the reaction mixture is poured into saturated aqueous NaHCO3 and extracted twice with CH2Cl2. The combined extracts are dried over Na2SO4 and concentrated in vacuo. The residue is purified by flash chromatography on silica gel, eluting with 2:1 hexanes:EtOAc (+0.5% Et3N). Fractions containing product are concentrated and subjected again to flash chromatography on silica gel. Elution with 2:1 hexanes:EtOAc (+0.5% Et3N) affords (26%) of 2-(1-ethoxymethyl-1H-imidazol-2-yl)-thiazole as a bright yellow oil. 1H NMR (400 MHz, CDCl3) δ 7.82 (d, J=3.2 Hz, 1H), 7.33 (d, J=3.2 Hz, 1H), 7.20 (d, J=1.2 Hz, 1H), 7.15 (d, J=1.2 H, 1H), 6.03 (s, 2H), 3.56 (q, J=7.2 Hz, 2H), 1.17 (t, J=7.2 Hz, 3H) ppm.
読み込み中…
