Trifluoroacetic acid → 5-Amino-2-chloro-isonicotinic acid

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Reaction Steps

A stirred suspension of 5-[N-(tert-butoxycarbonyl)amino]-2-chloropyridine-4-carboxylic acid (1.91 g, 7 mmol) in CH2Cl2 (200 mL) is treated slowly with trifluoroacetic acid until homogeneous (ca. 12 mL). The solution is stirred overnight and extracted with dilute NH4OH, and the aqueous layer is then acidified with dilute HCl to gave a precipitate of 5-amino-2-chloropyridine-4-carboxylic acid (1.05 g, 87%i yield). 1H NMR (DMSO) δ 9.01 (2H, m), 8.03 (1H, s) 7.48 (1H, s).

Provenance & Evidence