5-Aminopyrazine-2-carbonitrile → Tert-butyl 3-((2-(5-cyanopyrazin-2-ylamino)-5-nitropyridin-4-ylamino)methyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Palladium (II) acetate (39 mg, 0.17 mmol) was added to (±)-2,2″-bis(diphenylphosphino)-1,1″-binaphthalene (321 mg, 0.51 mmol) in DMF/toluene (1/1 15 mL) and the resulting mixture was degassed under a stream of nitrogen gas for 10 min. 2-Amino-5-cyanopyrazine (210 mg, 1.7 mmol), sodium tert-butoxide (250 mg, 2.6 mmol) and tert-butyl 3-((2-bromo-5-nitropyridin-4-ylamino)methyl)piperidine-1-carboxylate (713 mg, 1.7 mmol) were added and the mixture was degassed for a further 5 minutes then heated at 150° C. for 30 min using microwave irradiation. The mixture was concentrated in vacuo and water and ethyl acetate were added. The aqueous phase was extracted three times with ethyl acetate. The combined organic phases were dried (Na2SO4) and concentrated. The residue was purified by flash column chromatography on silica, eluting with a gradient of ethyl acetate in hexane, 10-100% over 50 min. The fractions containing the product contaminated with 2-amino-5-cyanopyrazine were combined, evaporated and repurified by silica column chromatography, eluting with a gradient of ethyl acetate in hexane, 10-50% over 45 min. Tert-butyl 3-((2-(5-cyanopyrazin-2-ylamino)-5-nitropyridin-4-ylamino)methyl)piperidine-1-carboxylate was obtained as a yellow solid (265 mg, 34%).

Provenance & Evidence