[Synthesis]
Example 32: Synthesis of 7-chloro-3,4-dihydroisoquinoline (Int-50)
To a solution of 7-chloro-1,2,3,4-tetrahydroisoquinoline (1.15 g, 6.86 mmol) in dichloromethane (DCM, 70.0 mL) was added manganese dioxide (MnO2, 5.96 g, 68.6 mmol) at room temperature. The reaction mixture was stirred for 16 hours. Upon completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad and the residual solids were washed several times with dichloromethane (DCM). The filtrates were combined and concentrated under reduced pressure to give the crude product. The crude product was purified by ISCO silica gel column chromatography (40 g silica gel, eluent 50% ethyl acetate (EtOAc) in dichloromethane (DCM) solution at a flow rate of 50 mL/min) to give 915 mg of the title compound 7-chloro-3,4-dihydroisoquinoline as a colorless solid.
NMR hydrogen spectrum (400 MHz, DMSO-d6) δ 8.35 (t, J = 2.1 Hz, 1H), 7.52 (d, J = 2.2 Hz, 1H), 7.46 (dd, J = 8.0, 2.3 Hz, 1H), 7.28 (d, J = 8.0 Hz, 1H), 3.70-3.63 (m, 2H), 2.71-2.65 ( m, 2H). |