Iodine → 5-Chloro-3-hydroxy-3-(2-methoxyphenyl)indolin-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

40 g (1.65 mol) magnesium shavings were overlaid with 100 ml ether, and after the addition of a small amount of iodine, they were carefully heated until the reaction kicked off. 203 ml (1.65 mol) bromanisole, dissolved in 450 ml ether, were dropped in to the boiling solution so slowly that the reaction continually proceeded at a low boil. Subsequently, with slight cooling to 20° C., 75 g (0.41 mol) 5-chlorisatin in 750 ml water-free tetrahydrofurane were added in by drops. After this, everything was stirred for 30 minutes more at room temperature. The reaction solution was poured into an aqueous NH4Cl solution while being stirred. This aqueous phase was extracted a number of times with ethyl acetate and the combined aqueous phases were washed with water four times, dried and concentrated in a vacuum. The residue obtained was crystallised from isopropanol, wherein 106 g of the intermediate product resulted.

Herkunft & Nachweise