Compound 36 (1.0 g, 3.98 mmol) was suspended in CH2Cl2 (10 mL); NaH (0.75 g, 12.0 mmol, 3 eq.) was added. The mixture was stirred at room temperature for 5-10 min; then 3-dimethylamino-1-propyl chloride hydrochloride (0.75 g, 4.74 mmol, 1.2 eq.) was added. The reaction mixture was heated to 70° C., kept at this temperature for 2 h (TLC monitoring, eluent: CH2Cl2-ethyl acetate, 1:1—the presence of initial carbazole, CHCl3-MeOH, 9:1—purity of the product). The resulting mixture was diluted with water, extracted with ethyl acetate, evaporated, and purified on a short thick column with silica gel, eluent: CHCl3-MeOH 99:1→90:10. Yield of 37: 0.84 g (63%).
