2-Aminoadamantane → 1-tert-butyl-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid (5-hydroxy-adamantan-2-yl)-amide

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Reaction Steps

To a stirred solution of 1-tert-butyl-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid (2.334 g; 9.88 mmol) in N,N-dimethylformamide/methylene chloride (1:4 ratio, 15 mL) at room temperature was added diisopropylethylamine (9.00 mL; 51.13 mmol). TSTU (5.420 g; 18.0 mmol) was then added. The resulting mixture was allowed to stir at room temperature for 2 hr and then 2-adamantylamine (1.654 g; 9.89 mmol) was added. The mixture was allowed to stir over night at room temperature and then concentrated in vacuo. The residue was partitioned between ethyl acetate and water. The organic layer was washed sequentially with 0.5N HCl, saturated sodium bicarbonate then brine, dried over sodium sulfate, filtered and concentrated in vacuo to give the crude product as a light brown solid. Purification by column chromatography (RediSep-120 g silica gel, 10%—100% ethyl acetate/hexanes) provided the desired trans-isomer of 1-tert-butyl-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid (5-hydroxy-adamantan-2-yl)-amide (1.23 g, 32%) as a white solid. by resulting light yellow gum was triturated with diethyl ether to provide 1-tert-butyl-5-chloro-1H-pyrazole-4-carboxylic acid adamantan-2-ylamide (4.02 g, 80%) as a white powder. The cis-isomer was also isolated (1.58 g, 41%).

Provenance & Evidence