C([O:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=1[C:11](Cl)=[O:12])(=O)C.[CH2:14](N(C(C)C)C(C)C)C.[CH3:23][C:24]([C:27]([OH:29])=[O:28])([CH3:26])[NH2:25]>C1(C)C=CC=CC=1>[OH:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=1[C:11]([NH:25][C:24]([CH3:26])([CH3:23])[C:27]([O:29][CH3:14])=[O:28])=[O:12]To a solution of 2-(chlorocarbonyl)phenyl acetate (20 mmol, 3.96 g) in toluene (50 ml) were N-ethyl-N,N-diisopropylamine (22 mmol, 2.84 g) and 2-methylalanine (22 mmol, 2.27 g) added. After stirring the reaction mixture at room temperature overnight, the mixture was diluted with 250 ml toluene and was washed with 1.8% HCl/aq (250 ml) and sat. NaCl/aq (250 ml). The organic phase was dried over Na2SO4 and concentrated under reduced pressure. The residue was dissolved in MeOH (50 mL) and 3 drops of conc. H2SO4 were added. The mixture was refluxed for 2 hours and concentrated under reduced pressure. The residue was dissolved in 250 mL EtOAc and washed with sat.NaHCO3/aq (250 ml) and sat. NaCl/aq (250 ml). The organic phase was dried over Na2SO4 and concentrated at reduced pressure. The resulting crude material was used without further purification.
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