Ammonia → Tert-butyl 4-(4-carbamoyl-2-oxo-2,3-dihydroimidazol-1-yl)piperidine-1-carboxylate

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Reaction Steps

A solution of 1-[1-(tert-butoxycarbonyl)piperidin-4-yl]-2-oxo-2,3-dihydro-1H-imidazole-4-carboxylic acid (210 mg, 0.675 mmol), N-[3-(dimethylamino)propyl]-N′-ethylcarbodiimide hydrochloride (388 mg, 2.02 mmol), 1H-1,2,3-benzotriazol-1-ol hydrate (273 mg, 2.02 mmol), N,N-diisopropylethylamine (0.352 mL, 2.02 mmol), and ammonia (0.5 M, 2.02 mmol, 4.05 mL) were stirred at room temperature in dimethylformamide (10 mL). After 3 h, the reaction was worked up with dichloromethane and saturated sodium bicarbonate. The organic extracts were washed with brine, dried over sodium sulfate, filtered and concentrated. Purification by silica gel chromatography (100% dichloromethane→15% methanol {1% ammonium hydroxide}/dichloromethane) gave the title compound (78 mg). MS 255.2 (M+1-tert butyl)

Provenance & Evidence