Sodium Nitrate → (7-Bromo-4-chloro-1-ethyl-1H-imidazo[4,5-c]pyridin-2-yl)hydroxyiminoacetonitrile

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Reaction Steps

A solution of N-[5-bromo-2-chloro-4-(ethylamino)-3-pyridinyl]-2-cyanoacetamide III, (458 g, 1.45 mol) in glacial acetic acid (4.6 L) was heated to 100° C. After 3 h, LC/MS analysis indicated that the conversion to (7-bromo-4-chloro-1-ethyl-1H-imidazo[4,5-c]pyridin-2-yl)acetonitrile (IV) was completed. After allowing to cool to ambient temperature, the reaction was charged with sodium nitrate (230 g, 3.34 mol) in portions. Vigorous gas evolution and foaming was observed together with a ˜10° C. exotherm. After stirring at ambient temperature for 16 h, the solid was collected by filtration and dried to a constant weight to give 545 g of the desired product (V) as a light yellow solid. This was used in the next step without further purification. MS (ES+) m/z 328 (M+H)+.

Provenance & Evidence