Preparation and reaction of phenol

it contain preparation and reaction of phenol

1. Preparation and Reaction of Phenol

2. Preparation of phenol

3. In Dow's process   method  chlorobenzene is heated with aq. NaOH at about 623k and 300 atm. pressure to form sodium phenoxide , which is acidified by dilute acid like HCl to form  phenol .

4. To   prepare phenol ,  cumene  is first oxidized in the presence of air of  cumene  hydro-peroxide. Then,  cumene  hydroxide is treated with dilute acid to  prepare phenol  and acetone as by-products.

5. Fusion of sodium benzene sulfonate with solid NaOH at 300 C followed by treatment with dilute HCl

6. Warming a solution of benzene diazonium chloride prepared from aniline on a water bath at 50C

7. From Coal tar Coal tar provides natural source of phenol and cresol. The middle oil fraction of coal tar contains phenols, cresols and naphthalene.[ 170-240 C] Oil when cooled solid naphthalene deposit. Centrifuge and the oil left out is agitated with NaOH gives phenols and cresols.

8. Reaction of phenol

9. Formation of salt Phenol is acidic It react with sodium hydroxide or sodium metal to form salts

10. Phenol is weakly acidic than carboxylic acid. It does not react with sodium carbonate and sodium bi cabonate

11. Reaction with FeCl3 phenol give violet colour on treatment with FeCl3 due to formation of complex. This reaction is given by most of the phenols

12. Formation of esters- alkali react with phenol to form phenoxide which will react with acid chloride to form phenyl esters

13. Formation of ether- phenol react with alkyl halide in alkali solution form phenyl ethers.

14. Phenol distilled with zinc dust yield benzene in low amount

15. Halogenation: Phenol with bromine in water give precipitate of 2,4,6 tribromo phenol. C hlorine behave in the same manner

16. Halogenation: Phenol with bromine in CS2/CCl4 give precipitate of 2,4,6 tribromo phenol. C hlorine behave in the same manner

17. Nitration : Phenol on nitration with dilute nitric acid gives a mixture of ortho and para nitro phenol

18. Nitration : Phenol on nitration with Concentrated nitric acid gives a mixture of ortho and para nitro phenol

19. Sulfonation : when phenol react with concentrated sulphuric acid at 20 C , Ortho phenolsulfonic acid is the main product and at 100 C, Para phenol sulfonic acid is the main product

20. Reimer Tiemann reaction of phenol

21. Reimer Tiemann reaction of phenol The  Reimer Tiemann reaction  is an organic chemical  reaction  where  phenol  is converted into an ortho hydroxy benzaldehyde using chloroform, a base, and acid workup. This name  reaction  can also be described as the chemical  reaction  used for the ortho -formylation of  phenols .

22. Mechanism of Reimer Tiemann reaction

23. Mechanism of Reimer Tiemann reaction Chloroform ( 1 ) is deprotonated by a strong base (normally hydroxide) to form the chloroform carbanion ( 2 ) It will quickly alpha-eliminate to give  dichlorocarbene ( 3 ); this is the principal reactive species. The hydroxide will also deprotonate the phenol ( 4 ) to give a negatively charged phenoxide ( 5 ).

24. Mechanism of Reimer Tiemann reaction The negative charge is delocalised into the aromatic ring, making it far more nucleophilic. Nucleophilic attack on the dichlorocarbene gives an intermediate dichloromethyl substituted phenol ( 7 ). After basic hydrolysis, the desired product ( 9 ) is formed .

25. The Kolbe –Schmitt   reaction  or  Kolbe  process (named after Hermann  Kolbe  and Rudolf Schmitt) 

26. Kolbe’s process is a carboxylation chemical  reaction  that proceeds by heating sodium phenoxide (the sodium salt of  phenol ) with carbon dioxide under pressure (100 atm , 125 °C), then treating the product with sulfuric acid.

27. The Kolbe reaction can be classified as a carboxylation chemical reaction. The reaction occurs when sodium phenoxide is allowed to absorb carbon dioxide and the resulting product is heated at a temperature of a 125-degree celsius and a pressure of over a hundred atmospheres. An unstable intermediate is now formed. This unstable intermediate goes through a proton shift, leading to the formation of sodium salicylate. Now, this mixture is treated with sulfuric acid. The acidification of the mixture yields the salicylic acid. 

28. Gattermann Reaction- it involves the treatment of phenol with a mixture of hydrogen cyanide and hydrogen chloride in the presence of aluminium chloride as catalyst . Salicylic acid is formed.

29. Fries rearrangement When ester of phenols heated with AlCl3 the acyl group migrates from the phenolic oxygen to an ortho or para position of the ring thus yielding a ketone

30. Phenol couple with benzene diazonium chloride in alkaline medium form P- hydroxyazobenzene

31. Phenol with phthalic anhydride in the presence of sulfuric acid to form phenolphthalein

32. Reaction of phenol with formaldehyde

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