39856-58-1

Light yellow Cryst

Used in a palladium-catalyzed synthesis of indole systems containing fused medium- and large-ring heterocycles. pyrrole derivatives ahs been prepared using 3-Amino-2-bromopyridine. Used in P-C coupling reaction.

Preparation of Example S-1: 2-Bromo-3-nitropyridine (3 g, 15 mmol) was dissolved in a solvent mixture of tetrahydrofuran (15 mL) and water (5 mL), followed by the addition of iron powder (1 g, 18 mmol) and ammonium chloride (2 g, 37 mmol). The reaction mixture was stirred at 60°C to 70°C for 5 hours. Upon completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad and the filtrate was washed with brine and extracted with ethyl acetate. The organic layers were combined, dried with anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography (eluent: ethyl acetate/hexane=1:4) to afford 2-bromo-3-aminopyridine (2.6 g, 15 mmol, quantitative yield).1H-NMR (DMSO-d6) δ (ppm): 5.47 (2H, brs), 7.07-7.09 (2H, m), 7.54 (1H, dd, J=). 2.0,3.6Hz).

[1] Patent: EP1782811, 2007, A1. Location in patent: Page/Page column 63
[2] Patent: EP1669348, 2006, A1. Location in patent: Page/Page column 71
[3] Bulletin de la Societe Chimique de France, 1992, # 1, p. 79 - 84
[4] Journal of the Chemical Society, 1952, p. 2042,2044
[5] Tetrahedron, 2002, vol. 58, # 17, p. 3323 - 3328