反应详情

温度

65 °C

1,5-Dibromopyridine (98%) was purchased from Lancaster Chemical Company. Sodium ethoxide (96%) and N,N-dimethylformamide (DMF) (99.9+ %. HPLC grade) were purchased from Aldrich Chemical Company. Under a nitrogen atmosphere, a mixture of3,5-dibromopyridine (5.00 g, 21.1 mmol). sodium ethoxide (2.87 g, 42.2 mmol), and DMF (10 mL) was stirred and heated at 65° C. for 15 h. The mixture was poured into water (70 mL), and anhydrous diethyl ether (155 mL) was added. Because of insoluble solids, it was necessary to filter both phases. The aqueous layer was separated and extracted with ether (2 ×25,3 ×50 mL). The combined ether extracts were dried (MgSO4), filtered, and concentrated by rotary evaporation, producing a dark-brown syrup. The brown residue was purified by vacuum distillation, affording 0.76 g (17.9%) of an oil, bp 105° C. at 5 mm Hg. 1HNMR(CDCl3): δ 9.12 (br s, 1H), 8.83 (br s, 1H), 8.42 (dd, 1H), 4.41(q,2H), 1.42(t, 3H). 13C NMR (CDCl3): δ 142.72, 136.50. 1.23.78. 64.31.14.:57.

1. additionwas added
2. filtrationto filter both phases
3. customThe aqueous layer was separated
4. extractionextracted with ether (2 ×25,3 ×50 mL)
5. dry with materialThe combined ether extracts were dried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated by rotary evaporation
8. customproducing a dark-brown syrup
9. distillationThe brown residue was purified by vacuum distillation