反应详情

To a suspension of potassium tert-butoxide (89 mg, 0.75 mmol) in THF (3 mL) is added methyl isocyanoacetate (65 μL, 0.68 mmol) followed by (S)-2-phenyl-4-(1-isothiocyanato-2-(4-nitrophenyl)ethyl)thiazole, 43, (250 mg, 0.68 mmol). The reaction mixture is stirred at room temperature for 2 hours then poured into sat. NaHCO3. The mixture is extracted with EtOAc (3×25 mL) and the combined organic layers are washed with brine and dried (Na2SO4) and concentrated in vacuo. The crude residue is purified over silica to afford 323 mg (˜100% yield) of the desired product as a slightly yellow solid. 1H NMR (300 MHz, CDCl3) δ 8.09-8.13 (m, 2H), 7.95-7 98 (m, 3H), 7.84 (d, J=1.2 Hz, 1H), 7.44-7.50 (m, 3H), 7.28-7.31 (m, 2H), 7.96 (d, J=0.6 Hz, 1H), 4.71-4.78 (m, 1H), 3.92 (s, 3H), 3.60 (dd, J=13.8 and 6.0 Hz, 1H), 3.45 (dd, J=13.8 and 6.0 Hz, 1H).

1. extractionThe mixture is extracted with EtOAc (3×25 mL)
2. washthe combined organic layers are washed with brine
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated in vacuo
5. customThe crude residue is purified over silica