Indole → 1-(4-Chlorobenzyl)-1h-indole

Beteiligte Stoffe

Reaktionsschritte

A mixture of 11.72 g (0.1 mole) of indole, 17.71 g (0.11 mole) of 4-chlorobenzyl chloride, 33 g (0.5 mole) of 85% KOH, 14 mL of H2O, 2.5 g (2.5 mmoles) of PEG-1000 and 100 mL of toluene was stirred and heated at 55°-65° for 22 hours. After cooling to room temperature, 50 mL of H2O was added. The layers were separated. The aqueous layer was extracted with 100 mL of toluene. The combined organic phases were washed with 2N HCl (2×50 mL), H2O (2×50 mL), and 50 mL of brine and dried over MgSO4. Evaporation of the solvent left 29 g of orange-brown oil. The oil was chromatographed on a 1100 g column of silica gel. The column was eluted with 1:1 CH2Cl2 -Skellysolve B and 200 mL fractions were collected. The fractions were assayed by silica gel tlc (1×4") (25% CH2Cl2 -Skellysolve B). Fractions 12-19 were combined giving 23.11 g of crude product as a pink oil The oil was chromatographed on a 1100 g column of silica gel. The column was eluted with 25% CH2Cl2 -Skellysolve B and 200 mL fractions were collected. The fractions were assayed as before. Fractions 20-30 were combined giving 20.33 g (84%) of 1-(4-chlorobenzyl)indole as a yellow oil.

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