反应详情

温度

-78 °C

In an oven dried nitrogen purged 3 neck 50 mL round bottom flask, 1.00 g (0.624 mmol) of 1,5,6-trimethylbenzimidazole in 2 mL of dry tetrahydrofuran is cooled to −78° C. 0.881 mL (1.498 mmol) of 1.7 M t-butyllithium in hexanes is added and the reaction mixture is stirred at −78° C. for 1 h. 0.154 g (0.686 mmol) of NIS in 2 mL of dry tetrahydrofuran is added. Reaction is removed from bath and stirred at room temperature for 1 hour, quenched with saturated aqueous solution of ammonium chloride, and diluted with dichloromethane. The layers are separated, the aqueous is extracted 3×25 mL dichloromethane, dried (MgSO4), and concentrated. The crude mixture is purified by chromatography using hexanes:ethyl acetate as a solvent system. The product containing fractions are combined to obtain 0.055 g of the title compound, 31% yield. MS, ES+=287.0 (M+1); 1H NMR (DMSO-d6) δ 7.337-7.324 (d, 2H); 3.684 (s, 3H); 2.309 (s, 3H); 2.275 (s, 3H) ppm.

1. customReaction
2. customis removed from bath
3. stirringstirred at room temperature for 1 hour
4. customquenched with saturated aqueous solution of ammonium chloride
5. additiondiluted with dichloromethane
6. customThe layers are separated
7. extractionthe aqueous is extracted 3×25 mL dichloromethane
8. dry with materialdried (MgSO4)
9. concentrationconcentrated
10. customThe crude mixture is purified by chromatography
11. additionThe product containing fractions