Reaktion #598240

Reaktionsgleichung

bromine

2-iodo-9,10-dihydrophenanthrene

bromine

sodium hydrogensulfite

→

2-bromo-7-iodo-9,10-dihydrophenanthrene

Lösungsmittel

trimethyl phosphate

trimethyl phosphate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Filtration, and the precipitated product is filtered off with suction
2. 2
   Waschenwashed with sat. sodium hydrogen-carbonate soln
3. 3
   Trocknenand dried over sodium sulfate
4. 4
   SonstigeThe solvent is removed in vacuo
5. 5
   Sonstigethe residue is recrystallised from heptane/toluene

Vorschrift

9.5 g (27.9 mmol) of 2-iodo-9,10-dihydrophenanthrene are dissolved in 40 ml of trimethyl phosphate, and a solution of 2 ml (39 mmol) of bromine in 10 ml of trimethyl phosphate is added dropwise at 20° C. After 90 min, the batch is added to ice-water, excess bromine is reduced by addition of sodium hydrogensulfite soln., and the precipitated product is filtered off with suction, taken up in toluene, washed with sat. sodium hydrogen-carbonate soln. and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is recrystallised from heptane/toluene, giving 2-bromo-7-iodo-9,10-dihydrophenanthrene as colourless crystals.

Quelle