Nitric Acid → (S)-2-amino-6-(2-fluoro-5-nitro-phenyl)-3,5,5,6-tetramethyl-5,6-dihydro-3H-pyrimidin-4-one

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Reaction Steps

To a solution of [(S)-4-(2-fluoro-phenyl)-1,4,5,5-tetramethyl-6-oxo-1,4,5,6-tetrahydro-pyrimidin-2-yl]-carbamic acid tert-butyl ester (intermediate E7, 0.27 g) in sulfuric acid (98%, 3.1 ml) was added at 0° C. fuming nitric acid (0.05 ml) and the reaction mixture was allowed to warm to 22° over 30 min. The mixture was slowly added to 20 ml ice cold water, the pH was adjusted to 7 using aqueous 4N NaOH and extracted with ethyl acetate. The organic layer was washed with water, dried and evaporated to give crude (S)-2-amino-6-(2-fluoro-5-nitro-phenyl)-3,5,5,6-tetramethyl-5,6-dihydro-3H-pyrimidin-4-one (0.19 g) as a pale orange amorphous solid. MS (ESI): m/z=309.2 [M+H]+.

Provenance & Evidence