Bicarbonate Ion → 2-(tert-butylamino)-4-((1S,3S)-3-hydroxy-4,4-dimethylcyclohexylamino)pyrimidine-5-carboxamide

Participants

Reaction Conditions

Reaction Steps

To a stirring suspension of 2-(tert-butylamino)-4-(methylsulfinyl)pyrimidine-5-carboxamide (375 mg, 1.46 mmol) and a mixture of (1R,5R)-5-amino-2,2-dimethylcyclohexanol hydrochloride and (1S,5S)-5-amino-2,2-dimethylcyclohexanol hydrochloride (342 mg, 1.902 mmol) in DMF (4.877 mL) was added DI EA (0.767 mL, 4.39 mmol) and the reaction was heated to 90° C. overnight. The crude reaction mixture was concentrated under reduced pressure and then purified using reverse-phased semi-preparative HPLC (5-80% acetonitrile+0.1% TFA in water+0.1% TFA, over 30 min). Fractions containing product were concentrated under reduced pressure and redissolved in a mixture of ethyl acetate (125 mL) and saturated aqueous sodium bicarbonate solution (50 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (75 mL). The combined ethyl acetate layers were dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The resulting residue was redissolved in a methanol (5 mL), passed over an Varian StratoSpheres HCO3 resin SPE tube for TFA removal (0.9 mmol bicarbonate equivalent), and then concentrated under reduced pressure to afford an oil that was triturated with diethyl ether and reconcentrated to give solids. The solids were dried for a few hours in a vacuum oven at 45° C. to afford a mixture of 2-(tert-butylamino)-4-((1R,3R)-3-hydroxy-4,4-dimethylcyclohexylamino)pyrimidine-5-carboxamide and 2-(tert-butylamino)-4-((1S,3S)-3-hydroxy-4,4-dimethylcyclohexylamino)pyrimidine-5-carboxamide (373 mg, 1.112 mmol, 76% yield).

Provenance & Evidence