反应详情

To a solution of 71 (0.82 g, 3.4 mmol) in anhydrous toluene (50 ml) were added 0.9 eq (1.10 g) of 4,5-dibromo-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole (compound 72, LCMS (method A): Rt: 3.60 min, ([M+H]+=357)) and the resulting mixture was stirred for 2 hours under N2 (room temperature). To this reaction mixture were added 10 mol % of PdCl2(PPH3)2 (240 mg). After the addition, the temperature was raised to 100° C. and the resulting solution was stirred for 18 hours under N2. The reaction mixture was cooled, diluted with ethyl acetate, washed three times with a saturated NaHCO3 solution, dried (Na2SO4), filtered and concentrated. The resulting residue was purified by flash chromatography (diethyl ether followed by ethyl acetate) to afford 3-[5-bromo-3-(2-trimethylsilanyl-ethoxymethyl)-3H-imidazol-4-yl]-pyridine (73) as an oil (385 mg, 36%). LCMS (method A): Rt: 3.40 min, ([M+H]+=355). 1H-NMR (400 MHz, CDCl3 and HMBC): δ 8.79 (d, J=2 Hz, 1H), 8.66 (dd, J=5 Hz, 2 Hz, 1H), 7.91 (dt, J=8 Hz, 2 Hz, 1H), 7.66 (s, 1H), 7.44-7.40 (m, 1H), 5.17 (s, 2H), 3.56-3.50 (m, 2H), 0.94-0.87 (m, 2H), 0.0 (s, 9H).

1. additionAfter the addition
2. temperaturethe temperature was raised to 100° C.
3. stirringthe resulting solution was stirred for 18 hours under N2
4. temperatureThe reaction mixture was cooled
5. washwashed three times with a saturated NaHCO3 solution
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customThe resulting residue was purified by flash chromatography (diethyl ether followed by ethyl acetate)