反应详情

1,1-Carbonyldiimidazole (1.60 g, 9.89 mmol) was added to a solution of 2-(tert-butoxycarbonylamino)-2-(4-chlorophenyl)acetic acid (2.57 g, 9.00 mmol) in CH2Cl2 (22.5 mL, 9.00 mmol), and the mixture was stirred for 30 minutes until gas evolution ceased. Hydrazine (0.367 mL, 11.7 mmol) was then added to this solution, and the mixture was stirred at room temperature for 12 hours. The reaction mixture was diluted with CH2Cl2 and washed with NaHCO3 (10%). The organic layer was dried (Na2SO4) and concentrated. The residue was purified by reversed-phase chromatography (Biotage SP4, 40+M, C18, 25% to 100% MeCN/H2O). Fractions containing product were poured into a separatory funnel and extracted with ethyl acetate (3×). The combined organic layers were dried and concentrated to give tert-butyl 1-(4-chlorophenyl)-2-hydrazinyl-2-oxoethylcarbamate as a solid (1.95 g, 72%). LCMS (APCI+) M+H+: 299 (5%); M+H+-Boc: 199 (100%); rt=2.78 minutes. 1H NMR (400 MHz, CDCl3) δ 7.73 (s, 1H), 7.30 (s, 4H), 5.85 (d, J=6.6 Hz, 1H), 5.21 (s, 1H), 3.87 (s, 2H), 1.42 (s, 9H).

1. stirringthe mixture was stirred at room temperature for 12 hours
2. washwashed with NaHCO3 (10%)
3. dry with materialThe organic layer was dried (Na2SO4)
4. concentrationconcentrated
5. customThe residue was purified by reversed-phase chromatography (Biotage SP4, 40+M, C18, 25% to 100% MeCN/H2O)
6. additionFractions containing product
7. additionwere poured into a separatory funnel
8. extractionextracted with ethyl acetate (3×)
9. customThe combined organic layers were dried
10. concentrationconcentrated