Yield:886373-00-8 80%

Reaction Conditions:

Stage #1: 5-bromo-2-ethoxy-3-nitropyridinewith tin(ll) chloride in ethyl acetate; for 2 h;Reflux;
Stage #2: with sodium hydroxide in water;ethyl acetate at 20;

Steps:

30.2

To a solution of 5-bromo-2-ethoxy-3-nitropyridine (75.2 mg, 0.304 mmol) in ethyl acetate (3 mL) was added tin(II) chloride (289 mg, 1.52 mmol), and the mixture was heated to reflux for 2 h. After cooling to rt, 50% aqueous sodium hydroxide was added dropwise until a sticky brown solid completely formed. Sodium sulfate was then added, and the mixture was stirred for several minutes. The solids were then removed by filtration. The filtrate was dried over sodium sulfate, filtered, and concentrated in vacuo to provide 5-bromo-2-ethoxypyridin-3-amine (53 mg, 0.25 mmol, 80% yield) as a dark blue film. ¹H NMR (400 MHz, CDCl₃) δ 7.56 (d, 1H), 6.97 (d, 1H), 4.37 (q, 2H), 3.85 (br s, 2H), 1.40 (dd, 3H); MS (EI) for C₇H₉BrN₂O: 217, 219 (Br isotopes, MH⁺).

References:

WO2010/135524,2010,A1 Location in patent:Page/Page column 237