PREPARATION OF PHENOLS
Summary
TLDRThe video explains various methods of preparing phenol, a crucial organic compound. It covers processes including treating chlorobenzene with NaOH, using benzene diazonium chloride, and methods involving benzene sulphonic acid, cumene, and Grignard reagents. The video also highlights the large-scale production of phenol from cumene, with acetone as a significant by-product. Additionally, it mentions oxidation and hydrolysis techniques involving benzene and salicylic acid to obtain phenol. The content is informative for those interested in organic chemistry and industrial phenol production.
Takeaways
- 🧪 Phenol, also known as carbolic acid, was first isolated from coal tar.
- 🧫 Chlorobenzene reacts with NaOH at 623 K and 320 atmospheric pressure to form sodium phenoxide, which gives phenol upon acidification.
- 💧 Benzene diazonium chloride, when warmed with water or treated with dilute acids, produces phenol.
- 🔬 Benzene sulphonic acid reacts with NaOH to form sodium phenoxide, which gives phenol upon acid treatment.
- 🍃 Cumene is oxidized to cumene hydroperoxide, which, when treated with dilute acid, yields phenol and acetone.
- 🧴 Acetone is a major byproduct in the industrial production of phenol via the cumene process.
- ⚗️ Grignard reagent (phenyl magnesium bromide) upon oxidation followed by hydrolysis in the presence of acid, forms phenol.
- 🌿 Sodium salicylate, when heated with soda lime, produces phenol.
- 🔥 Benzene reacts with H₂O₂ in the presence of HSO₃F to form phenol.
- 🔧 Benzene undergoes oxidation using V₂O₅ as a catalyst at 315°C to yield phenol.
Q & A
What is phenol and how was it first isolated?
-Phenol, also known as carbolic acid, was first isolated from coal tar.
How is phenol prepared from chlorobenzene?
-Chlorobenzene is treated with NaOH at 623 Kelvin and 320 atmospheric pressure to give sodium phenoxide, which upon acidification gives phenol.
How is phenol produced from diazonium salts?
-Benzene diazonium chloride is warmed with water or treated with dilute acids to yield phenol.
How can phenol be prepared from benzene sulphonic acid?
-Benzene sulphonic acid is treated with NaOH to produce sodium phenoxide, which upon acid treatment gives phenol.
What is the reaction mechanism for producing phenol from cumene?
-Cumene is oxidized in air to form cumene hydroperoxide, which, when treated with dilute acid, yields phenol and acetone.
What by-product is obtained alongside phenol in the cumene process?
-Acetone is obtained in large quantities as a by-product in the cumene process.
How is phenol produced from Grignard reagents?
-Phenyl magnesium bromide is subjected to oxidation followed by hydrolysis in the presence of an acid to produce phenol.
How is phenol prepared from salicylic acid?
-The sodium salt of salicylic acid is treated with soda lime, which gives phenol.
How can benzene be converted to phenol using H2O2?
-Benzene reacts with H2O2 in the presence of HSO3F to yield phenol.
What catalyst is used to produce phenol from benzene via oxidation?
-Vanadium pentoxide (V2O5) is used as a catalyst to oxidize benzene at 315°C to produce phenol.
Outlines
🔬 Phenol Preparation Methods
This paragraph discusses various methods of preparing phenol, starting with its isolation from coal tar. The text covers the treatment of chlorobenzene with sodium hydroxide at high temperature and pressure to form sodium phenoxide, which then converts to phenol upon acidification. It also mentions the conversion of benzene diazonium chloride to phenol by heating with water or dilute acids, and the treatment of benzene sulphonic acid with sodium hydroxide followed by acidification to produce phenol. Additionally, it explains the preparation of phenol from cumene hydroperoxide, obtained by oxidizing cumene. This method also yields acetone as a byproduct. Further, the paragraph covers the use of Grignard reagents and salicylic acid in phenol production. Finally, two methods involving the oxidation of benzene using H2O2 and vanadium pentoxide as catalysts are discussed.
Mindmap
Keywords
💡Phenol
💡Chlorobenzene
💡Sodium Phenoxide
💡Diazonium Salts
💡Cumene Process
💡Sodium Hydroxide (NaOH)
💡Benzene Sulphonic Acid
💡Acetone
💡Grignard Reagent
💡Salicylic Acid
Highlights
Phenol or carbolic acid was first isolated from coal tar.
Chlorobenzene is treated with NaOH at 623 K and 320 atmospheric pressure to give sodium phenoxide.
Sodium phenoxide upon acidification gives phenol.
Benzene diazonium chloride, when warmed with water or treated with dilute acids, gives phenol.
Benzene sulphonic acid treated with NaOH gives sodium phenoxide, which on acid treatment gives phenol.
Cumene oxidation with air produces cumene hydroperoxide, which on treatment with dilute acid gives phenol and acetone.
The reaction of cumene hydroperoxide produces acetone in large quantities along with phenol.
Most phenol production is derived from cumene.
Phenyl magnesium bromide oxidation followed by hydrolysis in the presence of an acid yields phenol.
Sodium salt of salicylic acid, when treated with soda lime, gives phenol.
Benzene reacts with H2O2 in the presence of HSO3F to give phenol.
Benzene, when oxidized in the presence of V2O5 as a catalyst at 315°C, produces phenol.
The process of treating benzene diazonium chloride with water or acids produces phenol.
Phenol can also be synthesized from benzene via hydroxylation using H2O2 and V2O5 catalysts.
Greenat Reagent: Oxidation of phenyl magnesium bromide followed by acid hydrolysis results in phenol.
Transcripts
preparation of
phenols from
hallerins phenol or carbolic acid was
first isolated from cold
tar chlorobenzene is treated with NaOH
at 623 Kelvin and 320 atmospheric
pressure pressure to give sodium
phenoxide which upon
acidification gives
phenol from diazonium
salts when Benzene diazonium chloride is
warmed with water or treating with
dilute acids gives
phenol from Benzene sulphonic acid when
Benzene sulphonic acid is treated with
NaOH it gives sodium phenoxide
which on treatment with acid gives
phenol from
cumine cumin
isopropoxides of air to give cumin
hydroperoxide which on treating with
dilute acid gives phenol and acetone
acetone in this reaction is also
obtained in large quantities most of the
phenol produ production is from cumin
from greenat
Regent when Phile magnesium bromide is
subjected to oxidation followed by
hydrolysis in presence of an acid gives
phenol from salicyclic Acid when sodium
salt of salicyclic acid is treated with
sodal lime it gives phenol from
Benzene one benzene upon hydroxy with
H2O2 in presence of
hso3f gives phenol two Benzene on
oxidation in presence of
v205 as Catalyst at a temperature of
315° C gives phenol
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