反应详情

At 0° C. to a solution of benzyl 2,5-dioxocyclopentanecarboxylate (2.58 g, 10.35 mmol) in MeOH (20 mL) was added 2-aminocyclohexanol (1.25 g, 10.87 mmol). The reaction mixture was stirred at room temperature for 18 h and quenched with 0.25 N HCl (8 mL). MeOH was removed under vacuum and the aqueous layer was extracted with CH2Cl2 (4×10 mL). The combined organic layers were washed with sat. NaCl (20 mL), dried over Na2SO4, filtered and concentrated. The residue was purified by ISCO chromatography (40 g column) using hexanes/EtOAc (0-5% over 15 min, 5-10% over 7 min) to give benzyl 2-hydroxycyclohexylcarbamate as a light yellow solid at a retention time of 11-13 min (2.15 g, 83% yield). HPLC: RT=2.83 min, Purity 95% (Phenomenex Luna C18 column, 4.6×50 mm eluting with 10-90% MeOH/H2O over 4 minutes containing 0.2% PPA; 4 mL/min, monitoring at 220 nm) NMR: 400 MHz 1H (CDCl3) 7.33 ppm, 5H, m; 5.16 ppm, 1H, m; 5.09 ppm, 2H, s; 3.95 ppm, 1H, s; 3.68 ppm, 1H, m; 1.54 ppm, 8H, m.

1. customquenched with 0.25 N HCl (8 mL)
2. customMeOH was removed under vacuum
3. extractionthe aqueous layer was extracted with CH2Cl2 (4×10 mL)
4. washThe combined organic layers were washed with sat. NaCl (20 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue was purified by ISCO chromatography (40 g column)
9. customhexanes/EtOAc (0-5% over 15 min, 5-10% over 7 min)