反应详情

Referring now to Scheme 4, a mixture of 6-chloronicotinonitrile (1.38 g, 10 mmol), 2,5-bis(tri-n-butylstannyl)furan (3.2 g, 5 mmol) and tetrakis(triphenyl-phosphine)palladium(0) (125 mg) in dry 1,4-dioxane (40 mL) was heated under nitrogen at reflux (100–110° C.) for 24 h. The solvent was evaporated under reduced pressure and the residue was dissolved in methylene chloride and the solution was passed through CELITE® matrix (available from Word Minerals Corporation of Santa Barbara, Calif., United States of America) to remove Pd. The solution was evaporated, filtered and the precipitate was washed with hexanes to afford 21 in 85% yield, mp 311–312° C. (DMF). 1H nmr (DMSO-d6); δ 7.55 (s, 2H), 8.20 (d, J=8.4 Hz, 2H), 8.44 (dd, J=8.4, 2.1 Hz, 2H). 9.06 (d, J=2.1 Hz, 2H). 13C nmr; δ 153.5, 152.8, 150.0, 141.0, 118.8, 117.1, 114.8, 107.3. Calcd. for C16H8N4O: C, 70.58; H, 2.96; N, 20.57. Found. C, 70.35; H, 3.04; N, 20.35.

1. temperaturewas heated under nitrogen
2. temperatureat reflux (100–110° C.) for 24 h
3. customThe solvent was evaporated under reduced pressure
4. dissolutionthe residue was dissolved in methylene chloride
5. customto remove Pd
6. customThe solution was evaporated
7. filtrationfiltered
8. washthe precipitate was washed with hexanes