Reaktion #344794

Reaktionsgleichung

2-methyl-3-nitrophenol

acetic anhydride

triethylamine

dimethylaminopyridine

→

4-acetoxyindole

Ausbeute 69.0%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigereported in Organic Synthesis, Coll
2. 2
   SonstigeThe catalyst was removed over a layer of Celite
3. 3
   Sonstigethe filtrate was evaporated under reduced pressure
4. 4
   Sonstigeto give an oily residue to which
5. 5
   Sonstigecrushed ice
6. 6
   workup.ADDITIONwas added
7. 7
   FiltrationThe resulting white precipitate was collected by filtration

Vorschrift

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).

Quelle