2-Chloro-3-fluoro-5-nitropyridine synthesis

Yield:1079179-12-6 97%

Reaction Conditions:

with phosphorus pentachloride;trichlorophosphate at 60; for 10 h;

Steps:

67.1 Step 1:
To a stirred solution of 3-fluoro-5-nitropyridin-2-ol (1.5 g, 9.48 mmol) in phosphorous oxychloride (15 ml_) was added phosphorous pentachloride (2.96 g, 14.22 mmol) at 60 °C. The reaction mixture was allowed to stir for 10h at the same temperature. The reaction mixture was cooled to ambient temperature and was poured into crushed ice and was extracted with ethyl acetate (3 x 20 mL). The total organic layer was washed with saturated sodium carbonate solution (25 ml_).The washed organic layer was dried over anhydrous magnesium sulfate and was concentrated under reduced pressure to obtain crude compound which was purified by using silica gel column chromatography (100-200 mesh, 5 % ethyl acetate in hexane) to afford 2-chloro-3-fluoro-5-nitropyridine (1.62 g, 97 %).

References:

GRÜNENTHAL GMBH;FRANK, Robert;CHRISTOPH, Thomas;LESCH, Bernhard;LEE, Jeewoo WO2013/13817, 2013, A1 Location in patent:Page/Page column 96; 97

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