Reaction Steps
To an ice-cold solution of 4-(3,4-dichlorophenyl)-7-methoxy-1,2,3,4-tetrahydroisoquinoline (2.65 g, 8.6 mmol) and N,N-diisopropylethylamine (1.8 mL, 10.3 mmol) in dichloromethane (80 mL) was slowly added a solution of 2-nitrobenzene-1-sulfonyl chloride (2.1 g, 9.5 mmol) in dichloromethane (10 mL). The mixture was stirred for 2 hours and then quenched with water. The organic layer was washed with brine, dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography (hexanes to ethyl acetate) to give 4-(3,4-dichlorophenyl)-7-methoxy-2-(2-nitrophenylsulfonyl)-1,2,3,4-tetrahydroisoquinoline (3.39 g, 80%) as a yellow solid: 1H NMR (CDCl3, 500 MHz) δ 7.80 (dd, J=8, 1.3 Hz, 1H), 7.67-7.63 (m, 1H), 7.58 (dd, J=7.9, 1.2 Hz, 1H), 7.54-7.50 (m, 1H), 7.15 (d, J=8.3 Hz, 1H), 7.02 (d, J=2.0 Hz, 1H), 6.87 (dd, J=8.3, 2 Hz, 1H), 6.81 (d, J=8.3 Hz, 1H), 6.75 (d, J=2.6 Hz, 1H), 6.73 (s, 1H), 4.77 (d, J=16.0 Hz, 1H), 4.56 (d, J=16.0 Hz, 1H), 4.18 (dd, J=4.9, 4.9 Hz, 1H), 3.82 (dd, J=13.2, 4.5 Hz, 1H), 3.81 (s, 3H), 3.63 (dd, J=13.1, 5.5 Hz, 1H).
