Lithium Chloride → 3-Bromo-7-[2-ethoxyvinyl]-1,5-naphthyridine

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Reaction Steps

A solution of 3,7-dibromo-1,5-naphthyridine (0.5 g, 1.74 mmol), tributyl-2-ethoxy-vinylstannane (1.91 mmol, 0.69 g), LiCl (8.7 mmol, 0.37 g) and 0.085 g of PdCl2(PPh3)2 in 50 mL of toluene was heated at 95° C. for 16 hr. After cooling off, 20 mL of a 2 M solution of KF was added to the mixture and stirring was continued for 0.5 hr. The mixture was diluted with 100 mL of CH2Cl2 and washed successively with a saturated solution of sodium bicarbonate, brine and water. The organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was chromatographed using 5% MeOH in CH2Cl2 to give the desired material in 55% yield. 1H NMR (CDCl3, 300 MHz) δ 1.40 (m, 3H), 4.05 (m, 2H), 5.85 (s, 1H), 7.25 (s, 1H), 8.15 (m, 1H), 8.55 (m, 1H), 8.85 (m, 2H). MS (ESI) [M+H]+ at 280.

Provenance & Evidence