Author Topic: PdCl2 in hydro->p-benzo rxn  (Read 4910 times)

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PdCl2 in hydro->p-benzo rxn
« on: December 04, 2002, 02:06:00 AM »
In the p-benzo wacker rxn by MethylMan, hydroquinone and PdCl2 are filtered out. SWIP's question is, could one take the PdCl2 and include it in the hydroquinone->p-benzo rxn, converting hydro to benzo without the pain of separating PdCl2 from hydroquinone? This may allow recycling of PdCl2 if it is plausible. SWIP uses the following hydro->benzo synth:

55 g of hydroquinone (and 2g of PdCl2 with the above variation), 115 g of isopropyl alcohol as a reaction medium, and 1 g of iodine as a catalyst were charged into a 300 ml four-necked glass reaction vessel with a stirrer, a dropping funnel, and a thermometer. Then stirring was started, and after 58 g of a 35% hydrogen peroxide solution were added over about 3 hours while keeping the temperature at 30-35°C, the temperature was raised to about 45°C, which was kept for about 3 hours to complete the reaction. After the completion of the reaction, the reaction mixture was cooled gradually to about 15°C, and the reaction product was filtered by suction. The reaction product was washed with a small amount of isopropyl alcohol, and dried under reduced pressure to yield 49.5 g of p-benzoquinone.

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