Answer to Question #16775 in Organic Chemistry for kenneth mcdonald

Question

How AND UNDER WHAT CONDITIONS DOES SULPHURIC ACID REACT WITH BENZENE AND ETHYLENE? Give equation , the condition s under which benzene can be converted to styrene and acetophenone. H=1 ;C= 12.

Answer 1

H₂SO₄ + C₆H₆ <=> C₆H₅-SO₃H + H₂O heat.catalyst.

Similarly, fuming sulphuric acid absorbs ethylene at room temperature to form ethyl
hydrogen sulphate, with much evolution of heat.

H₂SO₄ + H₂C=CH₂ <=> H₃C-CH₂-SO₄H

Another developing route to styrene is via benzene and ethane. This process is being developed by Snamprogetti S.p.A. and Dow. Ethane, along with ethylbenzene, is fed to a dehydrogenation reactor with a catalyst capable of simultaneously producing styrene and ethylene. The dehydrogenation effluent is cooled and separated and the ethylene stream is recycled to the alkylation unit. The process attempts to overcome previous shortcomings in earlier attempts to develop production of styrene from ethane and benzene, such as inefficient recovery of aromatics, production of high levels of heavies and tars, and inefficient separation of hydrogen and ethane. Development of the process is ongoing.

C₆H₆ + C₂H₆ --> C₆H₅-C₂H₅

C₆H₅-C₂H₅ ---> C₆H₅CH=CH₂ + H₂

By Friedel crafts acylation, ie treating benzene with any CH₃COX, where X is a halide (AlCl₃ t)

C₆H₆ + CH₃COX = C₆H₅-CO-CH₃ + HX