[CH2:1]([NH2:5])[CH2:2][CH2:3][CH3:4].C([Li])CCC.CCCCCC.[CH3:17][C:18]1([CH3:32])[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[NH:20][CH:19]1[C:27](OCC)=[O:28]>C1(C)C=CC=CC=1>[CH2:1]([NH:5][C:27]([CH:19]1[C:18]([CH3:32])([CH3:17])[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[NH:20]1)=[O:28])[CH2:2][CH2:3][CH3:4]Butylamine (15 ml) in toluene (40 ml) was cooled to −78° C. and a 2.5M solution of butyllithium in hexane (12.91 ml, 31.5 mmol) was added dropwise. After half an hour, ethyl 3,3-dimethylindoline-2(R/S)-carboxylate (4.600 g, 21 mmol) was added to the solution and this mixture was stirred under nitrogen for three hours. The mixture was then poured into a water/ice mixture (50 ml) and extracted with ethyl acetate; the extracts were dried over magnesium sulphate and the solvent was removed to give a brown oil. This was purified by chromatography on a column of silica gel, using a 7/3 petroleum ether/ethyl acetate mixture as eluent in order to give a yellow solid.
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