4-Toluenesulfonyl chloride → tert-butyl 7-bromo-5-tosyl-3,4-dihydro-1H-pyrido[4,3-b]indole-2(5H)-carboxylate

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Reaction Conditions

Reaction Steps

tert-Butyl 7-bromo-3,4-dihydro-1H-pyrido[4,3-b]indole-2(5H)-carboxylate (1.07 g, 3.04 mmol), 6 N NaOH solution (6 mL), (Bu4N)2SO4 (50% wt. solution in H2O, 0.20 mL), and TsCl (646 mg, 3.39 mmol) were combined in toluene (20 mL) and the resulting suspension was stirred at 25° C. for 1.5 h. H2O and EtOAc were added to the suspension and the phases were separated. The organic phase was washed with H2O, dried over Na2SO4 and concentrated under reduced pressure to afford the title compound (1.39 g, 91%) as a white solid: 1H NMR (300 MHz, CDCl3) δ 8.35 (s, 1H), 7.66 (d, J=6.6 Hz, 2H), 7.35 (d, J=8.2 Hz, 1H), 7.28-7.21 (m, 2H), 7.18 (d, J=8.1 Hz, 1H), 4.47 (s, 2H), 3.77-3.65 (br m, 2H), 3.11-3.03 (br m, 2H), 2.36 (s, 3H), 1.48 (s, 9H).

Provenance & Evidence