Sulfuric Acid → Pyridine-2-carboxylic acid [3-(2-chloro-acetylamino)-adamantan-1-yl]amide

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Reaction Conditions

Reaction Steps

Chloroacetonitrile (2.0 mL, 32 mmol) was cooled to 0° C. Sulfuric acid (1.0 mL, 19 mmol) was added slowly at 0° C. After addition completed, the mixture was stirred at 0° C. for 5 minutes. Pyridine-2-carboxylic acid (3-hydroxy-adamantan-1-yl)-amide (0.42 g, 1.56 mmol, from step 1) was added in one portion and the mixture was stirred at rt overnight. The thick solution was poured into ice-water (10 mL). DCM (10 mL) was added. While the mixture was cooled with an ice-bath, the pH of the aqueous phase (top) was adjusted to 10-13 with 10N ad. NaOH. The aqueous layer was extracted with DCM. The combined organic layer was washed with water and brine, dried over Na2SO4, and concentrated under reduced pressure to afford 0.53 g (96.9%) of crude title compound, pyridine-2-carboxylic acid [3-2-chloro-acetylamino)-adamantan-1-yl]-amide, as an oil, which became a colorless solid upon standing at room temperature. LC-MS (Gradient: acetonitrile in water, 20-85%, in 1.7 minutes with a cycle time of 2 min. Flow rate: 5.0 mL/min. Mobile phase additive: 30 mM of ammonium formate. Column: Inertsil® ODS, 50×4.6 mm, 3 μm particle size (GL Sciences, Tokyo, Japan)): Retention time: 1.08 min; purity (UV254): 100%; ESI-MS m/z: 348 (M+H)+. It was used in the next step without further purification.

Provenance & Evidence