反应详情

80.0 mg (0.33 mmol) of (R)-4-ethyl-1-[4-(trifluoromethyl)phenyl]-2-azetidinone produced in Example 6and 74.8 mg (0.50 mmol) of benzyl carbamate were dissolved in tetrahydrofuran (3 mL) and further mixed with a lithium tert-butoxide/tetrahydrofuran solution (1 mol/L, 0.50 mL, 0.50 mmol) at room temperature. After stirring at the same temperature for 1.5 hours, water (5.0 mL) was further added to the reaction solution and extraction with ethyl acetate (5 mL) was repeated three times. The residue obtained by concentrating the separated organic layer dried with anhydrous magnesium sulfate was purified on silica gel column chromatography to obtain benzyl (R)-{3-[4-(trifluoromethyl)phenylamino]-pentanoyl}carbamate as a white solid (112 mg, isolated yield: 86%). 1H-NMR (CDCl3, 400 MHz/ppm): δ 0.98 (3H, t), 1.5-1.8 (2H, m), 2.9-3.2 (2H, m), 3.8-3.9 (1H, m), 4.2-4.3 (1H, br), 5.17 (2H, s), 6.60 (2H, d), 7.3-7.4 (7H, m), 7.5-7.6 (1H, br)

1. customThe residue obtained
2. concentrationby concentrating the separated organic layer
3. dry with materialdried with anhydrous magnesium sulfate
4. customwas purified on silica gel column chromatography
5. customto obtain