[CH2:1]([C@H:8]1[CH2:12][O:11][C:10](=[O:13])[NH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C.[C:21](Cl)(=[O:25])[CH2:22][CH2:23][CH3:24]>CN(C)C1C=CN=CC=1.ClCCl>[CH2:1]([C@H:8]1[CH2:12][O:11][C:10](=[O:13])[N:9]1[C:21](=[O:25])[CH2:22][CH2:23][CH3:24])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1To a 3-necked RBF (round bottomed flask) is added dichloromethane (2.4 L), (S)-4-benzyl-2-oxazolidinone (200 g, 1.13 moles) and N,N-Dimethyl-4-pyridinamine, (13.6 g; 111.32 mmoles). The flask is cooled in an ice water bath and triethylamine (472 mL; 3.39 moles) is added dropwise at 0° C. To the resulting solution is then added dropwise butanoyl chloride (152.2 mL; 1.46 moles) over 3 h, while keeping the temperature below 5° C. The reaction is then filtered and the filtrate is washed with 1M HCl (aq.) (500 ml×1) and saturated NaHCO3 (500 ml×1). The organic phase is dried over Na2SO4, filtered, and concentrated to afford the title compound (275 g, MS:[M+H]+=248.1 m/z).
Wird geladen…