反应详情

PIFA was added to a stirred solution of tert-butyl 3-[4-[5-[bis(tert-butoxycarbonyl)amino]-6-ethynyl-pyrazin-2-yl]phenyl]sulfonylpiperidine-1-carboxylate (150 mg,) and (E)-2-hydroxybenzaldehyde oxime in MeOH/water (0.4 mL) and the reaction mixture stirred at ambient temperature for 1.5 hours. A further portion of PIFA was added and the reaction mixture stirred at ambient temperature for a further 1.5 hours. The reaction mixture was partitioned between ethylacetate and water and the layers separated. The aqueous layer was extracted with ethylacetate (×1) and the combined organic extracts dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by column chromatography (ISCO Companion, 24 g column, eluting with 0 to 50% Petroleum/Petroleum Ether, loaded in DCM) to give tert-butyl 3-((4-(5-((tert-butoxycarbonyl)amino)-6-(3-(2-hydroxyphenyl)isoxazol-5-yl)pyrazin-2-yl)phenyl)sulfonyl)piperidine-1-carboxylate as an off-white solid (142 mg, 78%). LC/MS m/z 722.1 [M−56+1]+.

1. stirringthe reaction mixture stirred at ambient temperature for a further 1.5 hours
2. customThe reaction mixture was partitioned between ethylacetate and water
3. customthe layers separated
4. extractionThe aqueous layer was extracted with ethylacetate (×1)
5. dry with materialthe combined organic extracts dried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe residue was purified by column chromatography (ISCO Companion, 24 g column, eluting with 0 to 50% Petroleum/Petroleum Ether, loaded in DCM)