2-(2,4-Difluoro-phenoxy)-5-nitro-isonicotinic acid methyl ester → 5-Amino-2-(2,4-difluoro-phenoxy)-isonicotinic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

Compound (1B) (7.99 g, 25.6 mmol) was taken up in EtOH (350 mL), and nitrogen gas was bubbled through the solution for five minutes before 10% Pd/C (1.6 g) was carefully added. The resulting mixture was put on the Parr Shaker under 60 psi hydrogen gas for 4 hours. By TLC, there was no starting material remaining. The reaction mixture was filtered through a 3 cm bed of celite, and the filtrate was concentrated to give 7.0 g of crude product. Purification by column chromatography eluting on 130 g of silica gel with a gradient of 5% EtOAc in hexanes through 10% EtOAc in hexanes afforded the titled compound (1C) as an off-white powder (4.223 g, (M+H)+=281, Mp=102.0–103.9° C.).

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