反应详情

Triethylamine (899.0 mg, 1.238 mL, 8.884 mmol) was added to a solution of tert-butyl N-tert-butoxycarbonyl-N-[3-ethynyl-5-(4-isopropylsulfonylphenyl)pyrazin-2-yl]carbamate 8 (4.05 g, 8.074 mmol) and 4-(chloromethyl)-N-hydroxy-benzimidoyl chloride (2.063 g, 8.494 mmol) in DCM (12 mL). The mixture was stirred at RT for 22 h then partitioned between DCM and an ice/water solution. The combined organic extract was dried over MgSO4 and concentrated under reduced pressure then purified by chromatography on silica gel (eluent 30-50% EtAc/petrol) yielding tert-butyl N-tert-butoxycarbonyl-N-[3-[3-[4-(chloromethyl)phenyl]isoxazol-5-yl]-5-(4-isopropylsulfonylphenyl)pyrazin-2-yl]carbamate as colourless crystals (4.53 g, 79%). 1H NMR (400 MHz, CDCl3) δ 1.41 (18H, s), 4.66 (2H, s), 7.37 (1H, s), 7.54 (2H, d, J=8.0 Hz), 7.90 (2H, d, J=8.0 Hz), 8.66 (1H, s)

1. customthen partitioned between DCM
2. extractionThe combined organic extract
3. dry with materialwas dried over MgSO4
4. concentrationconcentrated under reduced pressure
5. customthen purified by chromatography on silica gel (eluent 30-50% EtAc/petrol)