Bormination

Heat 1.1 g 2-ethoxycarbonyl-5-hydroxyindoIe(5-OH-indole and perhaps 5-OH-DMT will work) and 0.9 g powdered AICI3 at 145° in orthodichlorobenzene. Add 2-3 ml acetylchloride and keep the temperature at 145-150° for 2 hours. Cool and hydrolyze with ice cold 2N HCI. Extract with chloroform and dry, evaporate in vacuum to get 4-acetyl-2-ethoxy-carbonyl-5-hydroxyindole in ca. 50% yield. This paper also gives a method for borminating the starting cpd. in the 4 position. 

Bromination is catalyzed by Lewis acids, and a study of the kinetics of bromina-tion of benzene and toluene in the presence of aluminium chloride has been reported." Toluene is found to be about 35 times more reactive than benzene under these conditions. The catalyzed reaction thus shows a good deal less substrate selectivity than the uncatalyzed reaction, as would be expected on the basis of the greater reactivity of the aluminum chloride-bormine complex. 

Lel0 Lecemf, A., Bormin, A., Hardy, A. Compt Rend. 262C (1966) 352-355. 

Lahaye, M., Bmnel, M., and Bormin, E. (1997) Fine chemical structure analysis of oligosaccharides produced by an ulvan-lyase degradation of the water-soluble cell-wall polysaccharides from Ulva sp. (Ulvales. Chlorophyta). Carbohydr. Res., 304,325-333. 

---