Acetic Anhydride → 4-Acetoxyindole

Participants

Reaction Steps

A suspension of 3.24 g of trans-6-benzyloxy-2-nitro-β-pyrrolindino -styrene (prepared from 2-methyl-3-nitrophenol by a procedure reported in Organic Synthesis, Coll. Vol. 7, 34, 1990) and 648 mg of 10% pd/C catalyst in 30 ml of ethyl acetate was shaken under hydrogen atmosphere and at 50 psi, for 5 hours. To this reaction mixture were added acetic anhydride (1.4 ml), triethylamine (2.1 ml) and dimethylaminopyridine (324 mg). The resultant mixture was stirred for 1 hour at room temperature. The catalyst was removed over a layer of Celite and the filtrate was evaporated under reduced pressure to give an oily residue to which crushed ice was added. The resulting white precipitate was collected by filtration to give 1.2 g (69% yield) of 4-acetoxyindole: mp 97°-98° C.; HNMR (300 MHz, DMSO-d6)δ 2.32 (s,3H), 6.31 (s,1H), 6.71 (d,1H,J=8Hz), 7.05 (t, 1H, J=8 Hz), 7.28 (d,1H,J=8Hz), 7.32 (s,1H), 11.27 (s,1H).

Provenance & Evidence