C[N:2]1[CH2:6][CH2:5][CH:4]=[CH:3]1.[Li][CH2:8]CCC.[Cl:12][C:13]1[CH:20]=[CH:19][CH:18]=[CH:17][C:14]=1[CH2:15]Br.O>C1COCC1>[Cl:12][C:13]1[CH:20]=[CH:19][CH:18]=[CH:17][C:14]=1[CH2:15][CH2:8][C:3]1[CH2:4][CH2:5][CH2:6][N:2]=15.1 3 ml of 1-methylpyrroline are dissolved in 25 nil of THF and deprotonated at −78° C. for 30 minutes using 22.6 ml of BuLi (1 M in hexane). 6.5 g of 2-chlorobenzyl bromide are dissolved in 25 ml of THF and added dropwise at the temperature indicated. After 30 minutes, the mixture is allowed to warm to RT for 12 hours. For work-up, 50 ml of water are added, and the mixture is extracted to exhaustion with dichloromethane. The combined organic phases are dried over sodium sulfate, evaporated and purified by chromatography on silica gel, giving 4.5 g of 5-[2-(2-chlorophenyl)ethyl]-3,4-dihydro-2H-pyrrole as a colourless oil, which is employed in the next reaction; Rt.: 1.303 min; [M+H]+208.
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