反应详情

To the flask containing 21 (10 mmol) is added 7 mL of triethylamine followed by 100 mL of methylene chloride, 2.05 mL of pentafluorophenyl trifluoroacetate (PFP-TFA) is then added. The solution is stirred for half an hour. At the end of this time, the reaction is usually complete. (TLC: 2:1 hexane/ethyl acetate). The solvent is removed on the rotary evaporator to give a syrup which is chromatographed on silica eluting with 1:3 ethyl acetate/hexane. Appropriate fractions are collected, combined, evaporated and dried under vacuum. The yield is 41%. 1H NMR (DMSO-d6) δ8.43 (d, J=2.5 Hz, aromatic proton, 1H), 8.24 (dd, J1=9 Hz, J2=2.5 Hz, aromatic proton, 1H), 7.83 (d, J=9 Hz, aromatic proton, 1H), 7.78 (d, J=9 Hz, aromatic proton, 1H), 7.42-7.15 (m, aromatic protons, 10H), 7.07 (m, aromatic protons, 2H), 7.00-6.80 (m, aromatic protons, 4H), 3.72 (s, 2×CH3, 6H), 3.56 (m, aliphatic protons, 2H), 3.48 (t, J=6.3 Hz, aliphatic protons, 2H), 3.08 (t, J=5 Hz, aliphatic protons, 2H), 2.89 (t, J=7 Hz, aliphatic protons, 2H), 1.95 (m, aliphatic protons, 2H), 1.86 (m, aliphatic protons, 2H).

1. additionis then added
2. customThe solvent is removed on the rotary evaporator
3. customto give a syrup which
4. customis chromatographed on silica eluting with 1:3 ethyl acetate/hexane
5. customAppropriate fractions are collected
6. customevaporated
7. customdried under vacuum