反应详情

4.05 g (96.6 mmol) LiOH.H2O were dissolved in a mixture of 100 mL H2O, 30 mL methanol and 40 mL THF. 5.2 g (16 mmol) 9 were added and it was stirred at r.t. for 20 h, during this time turning into a yellow, homogeneous solution. Most of the THF and methanol were taken off by rotovapping, the remaining solution was acidified with 2 N HCl and extracted with ethyl acetate three times. The combined organic layers were washed with brine, dried with MgSO4 and put under vacuum, yielding 3.9 g (96%) of a yellow solid, which was pure by NMR. For characterization, a sample was recrystallized from ethyl acetate. mp 142° C.; 1H NMR (CDCl3) δ 8.53 (dd, J1=1.5 Hz, J2=2.4 Hz, 1H), 7.98 (t, J1=2.4 Hz, J2=2.4 Hz, 1H), 7.94 (dd, J1=1.5 Hz, J2=2.4 Hz, 1H), 4.14 (t, J=6.4 Hz, 2H, PhOCH2CH2CH(CH3)2), 1.99-1.80 (m, 1H), 1.80-1.70 (m, 2H), 1.01 (d, J=6.3 Hz, 6H, CH(CH3)2); 13C NMR (acetone-d6) 165.52, 160.75, 150.12, 133.90, 122.35, 116.67, 113.68, 68.41, 38.33, 25.68, 22.74; ESI-MS m/z 252 [M−1]+.

1. extractionextracted with ethyl acetate three times
2. washThe combined organic layers were washed with brine
3. dry with materialdried with MgSO4