5,6,7,8-Tetrahydroquinoline is prepared by the reaction of pyridine and 1,4-dichlorobutane. The specific synthesis steps are as follows:
At 25℃ and an inert atmosphere,Compound 2 (2.67 g, 21.02 mmol) was added to a suspension of aluminum chloride (0.20 g, 1.5 mmol) in pyridine (10 mL). After stirring the obtained orange solution for 24 hours, It was poured into an ice water mixture (50 g) and extracted with ethyl acetate (50 mL).The organic layer was separated and washed sequentially with water (50 mL). The organic layer was washed with saturated sodium bicarbonate solution (50 mL) and brine (50 mL). It was then dried over NaSO4 and concentrated in vacuo. The yellow oil was subjected to flash chromatography on silica gel (eluent: hexane), Obtaining 5,6,7,8-tetrahydroquinoline, 2.66 g, yield 95%.