Sulfuric Acid → Hexachlorobutadiene

Temperature

100 °C

In a 1 liter flask, a mixture of 78 g of concentrated sulphuric acid and 78.5 g of phosphorus pentoxide was poured onto 100 g of 96% pure hexachlorocyclobutene [96 g (0.368 mole) of hexachlorocyclobutene; remainder hexachloro-1,3-butadiene], with stirring (molar ratio of hexachlorocyclobutene:sulphuric acid:phosphorus pentoxide=1:2:1). The mixture was heated at 100° C. for 3 hours. After cooling, the reaction mixture was poured onto ice, the organic phase was then separated immediately from the aqueous phase and the latter was extracted three times with petroleum ether. The petroleum ether solution and the organic phase were combined and dried with sodium sulphate, the petroleum ether was distilled under normal pressure and the residue was subjected to fractional distillation under 35 mbars. 43.6 g of tetrachlorocyclobutenone, 14.3 g of hexachlorocyclobutene and 3.6 g of hexachloro-1,3-butadiene were obtained. The selectivity of the reaction was 69.0% of theory with a conversion of 85% of theory.

1. temperatureAfter cooling
2. additionthe reaction mixture was poured onto ice
3. customthe organic phase was then separated immediately from the aqueous phase
4. extractionthe latter was extracted three times with petroleum ether
5. dry with materialdried with sodium sulphate
6. distillationthe petroleum ether was distilled under normal pressure
7. distillationthe residue was subjected to fractional distillation under 35 mbars

ORD record

ord-7320193863ee491a874bebdab0adc6d6

Source dataset

uspto-grants-1981_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04272633