1-Benzyl-2,5-dihydro-1H-pyrrole

1476-11-5

100-46-9

6913-92-4

The general procedure for the synthesis of N-benzyl-3-pyrroline from cis-1,4-dichloro-2-butene and benzylamine was as follows: the synthesis was carried out according to the literature method with the following modifications: a) cis-1,4-dichloro-2-butene (0.76 g, 5.77 mmol) was dissolved in anhydrous dichloromethane (4 ml) at 5 °C; b) benzylamine was slowly added dropwise to the above solution ( 3.75 g, 34.66 mmol) to the above solution. The reaction mixture was stirred at 5°C for 10 min and then moved to room temperature and continued stirring for 24 hrs. After completion of the reaction, the resulting white solid was collected by filtration and washed with dichloromethane. The filtrate was cooled to 0°C, 37% hydrochloric acid (0.6 ml) was added, and the white solid was collected by filtration again and washed with dichloromethane. The filtrate was concentrated to give an orange oil, which was purified by fast chromatography (silica gel as stationary phase, hexane: ethyl acetate = 1:1 as eluent) to finally obtain N-benzyl-3-pyrroline (0.76 g, 82% yield) as a yellow oil. The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3) and 13C NMR (75 MHz, CDCl3): 1H NMR δ 7.38-7.21 (m, 5H), 5.78 (s, 2H), 3.80 (s, 3H), 3.81 (s, 2H), 3.48 (s, 4H); 13C NMR δ 139.67, 128.69, 128.34, 127.78, 126.96, 60.40, 59.70.