Chem F324

• High electron density in Pi-Ring system.
• Only substitute reactions.
• Higher freezing point than expected:
  • Packed planer rings --> Higher VDW forces.

Reactions:

• Electrophillic substitution
  • Addition of halogens requires catalyst
• C6H12 + X  --(FeCl3 catalyst)--> C6H11X + H+
• C6H12 + HNO3 --([H2SO4]catalyst, 50C temp)--> C6H11NO2 + H+
• C6H12 + R --(AlCl3 catalyst, 80C temp)--> C6H11R + H+
• C6H12 + C2H4 --(AlCl3 catalyst, 40ATMp 600K)--> C8H16
  • C8H16 --(Fe2O3 900K)--> C8H12 + 2H2

• Sparingly soluble in H2O.
• Partially Ionises in H2O ---> Weak acid.

Reactions:

• OH group:
  • C6H11OH + NaOH ---> C6H11ONa + H2O
  • C6H11OH + Na ---> C6H11ONa + 1/2H2
• Benzene Ring:
  • C6H11OH + 1.5Br2 ---> C6H9OHBr3 + 1.5H2
  • Also the case with C6H11NH2

Arenes are used to produce explosives, polymers, pharmacuticuls and dyes.

Phenol is used in anticeptics adn disinfectants.

Preparation:

• Phenyl amine prepared by reducing nitrobenzene
  • Sn and Conc HCl required.
• Reduction of Nitriles
  • [H2] and LiAlH3 required.
• Substitution of halogenoalkanes
  • Ethanol required.

Amines act as bases due to lone pairs of electrons forming dative covalent bonds wih H+.

Amines react with water to form a base:

RNH2 + H2O ----> RNH3+ + OH-

Anhydride + Alcohol ----> Ester + Carboxylic acid

Made by oxidising aldehydes or hydrolysing esters.

Reactions:

• Acid + Metal ----> Carboxylate + H2
• Acid + Metal acid ---> Carboxylate + H2O
• Acid + Metal carbonate ---> Carboxylate + H2O + CO2
• Carboxylic acid + Alcohol --[H2SO4]--> Ester + H2O           ((((ESTERFICATION))))

Used in flavourins and fragrances.

Hydrolysis:

• Use H+ /OH-
• Reflux
  • Acid ---> Carboxylic acid + Alcohol
  • Alkali ---> Carboxylate + Alcohol.

Oils and Fats can Be hydrolysed in the same was as Esters. The process is known as saponification.

• Bifunctional
  • COOH - proton donor
  • NH2 - proton acceptor
• Chiral Centers
  • Denoted as *
  • Optical isomers
• Undergo condenstation reactions
  • Create peptide linkages (amides).

Zwitter ions

• E/Z isomers.
• Optical Isomers.
  • Non superimposable mirror images.

Pharnalogically, only one optical isomer is useful. The other may have toxic effects. The correct isomer is used to reduce the dosage amounts and to also reduce the risks of sode effects.

• Addition polymers
  • Monomers ----> Alkenes
• Condensation polymers
  • Two products:
    • Polymer
    • A Small Molecule

3 types of condenstation polymers:

• Polyesters.
• Polyamides.
• Protiens & Polypeptides.

• Primary alcohol --[O]--> Aldhyde.
• Secondary alcohol --[O]--> Ketone.

2,4 DNPH is used to distinguish if aldehyde/ketone is present.

Distinguishing between Aldehyde and ketone:

• [O] = H/Cr2O7                                     Orange -----> Green.
• [O] = Tollens reagent                            Silver mirror formed.
• [O] = Fellings reagent                           Blue -----> Orange.