Aromatic Chemistry [9701]

Ay lowk, use this only fo revision.

What is the structure of benzene.

→ Each carbon atom is SP2 hybridized
→ The unhybridized P orbital in each carbon undergoes sideways overlap
→ Arrangement is trigonal planar with an angle of 120.
→ The hydrogen-carbon bond, is an SP2 carbon bonded with the s orbital of Hydrogen.

Why maybe benzene characterized different from alkenes?

→ Does not decolorize bromine (w/o catalyst)
→ Does not react with Hot/Cold KMnO4

What are the conditions and reagents for nitration of benzene.

→ HN03 + H2S04 (both concentrated and warmed, at 55C)

What will happen if during nitration of benzene the temperature to taken to over 60 degrees?

Further substitution takes place.

What type of group is NO2 group?

Electron withdrawing, will direct to 3 and 5 positions.

What is the catalyst used for bromination/chlorination of benzene.

AlCl₃ /AlBr₃

What is the difference of methylbenzene undergoing nitration and normal benzene undergoing nitration?

Methyl group is electron donating.
Makes Pie chain more reactive, and reaction happens are lower temperature (30C)

What do Friedel Crafts reaction require.

Acyl Chloride (R-COCl) + AlCl₃

What will happen to Alkyl groups bonded to benzene when it reacts with Hot KMn04?

Alkyl → COOH
forms benzoic acid.

What is the use of Diluted H2SO4 in oxidizing Alkyl chains connected to benzene?

Required for Protonation.

OH groups in phenol, electron donating or electron withdrawing?

Electron donating [2-4 positions]

Do Phenols react with Hydrogen carbonates or carbonates?

No.

Whenever phenol is required to react something, what is required?

NaOH → This will react with OH in the ring, and produce O^-Na⁺

What are the reagents and conditions required for nitration of phenol?

Dilute HNO3 at room temp.

What is the observation, when a phenol is chlorinated or brominated?

White PPT is produced.
all groups directed to 2-4-6

Why is chlorobenzene categorized unreactive?

All of lone pairs of chlorine will be delocalized into the pie ring of benzene, making it extremely stable.

How is phenylamine produced from nitrobenzene.

Sn + Hot conc. HCl

Why is Phenylamine weaker than Ammonia (in terms of basicity).

Nitrogen lone pairs are delocalized within the pie ring, makin it less available to form a dative bond.

What is the type of reaction of phenylamine and Acyl Chloride.

Condensation reaction.

Formation of diazonium salt required reagents and conditions.

NaNO2 + HCl + 5C Temp.

How is phenol produced from diazonium salt.

Reaction with water + heat —> Phenol + N2 + HCl produced

How is Azo Dye Produced from diazonium salt?

Diazonium salt reacting with Phenylamine/Phenol