反应详情

A mixture of 1-(5-bromo-pyridin-3-yl)-ethanone (200 mg, 1.000 mmol), ethanesulfonamide (136 mg, 1.250 mmol) and titanium(IV) isopropoxide (586 μL, 2.0 mmol) in toluene (20 mL) was heated to reflux for 8 h. After concentration, the residue was dissolved in THF (5 mL). A solution of methylmagnesium bromide (1000 μl, 3.00 mmol) was added dropwise at −50° C. The resulting mixture was slowly warmed up to room temperature over a course of 2 h. The mixture was stirred at this temperature overnight and quenched with NH4Cl solution. After filtration, wash with CH2Cl2 and concentration, the residue was purified by flash column (Ethyl acetate/heptane, v/v, 10% to 50%) and yielded a yellow oil (35 mg). ESI-MS m/z: 309.1 [M+1]+, Retention time=1.22 min. 1H NMR (400 MHz, CDCl3): δ 1.43 (t, J=7.4 Hz, 3H), 1.84 (s, 6H), 2.98 (q, J=7.4 Hz, 2H), 5.07 (brs, 1H), 8.04 (s, 1H), 8.66 (s, 1H), 8.77 (s, 1H).

1. temperaturewas heated
2. temperatureto reflux for 8 h
3. concentrationAfter concentration
4. dissolutionthe residue was dissolved in THF (5 mL)
5. customquenched with NH4Cl solution
6. filtrationAfter filtration
7. washwash with CH2Cl2 and concentration
8. customthe residue was purified by flash column (Ethyl acetate/heptane, v/v, 10% to 50%)