Module 6.2.4- Carbon-carbon bond formation

• Nitrile organic functional group

  -CN

  
• What is the need to form nitriles using CN

  To increase the length of a carbon chain so you are able to synthesise new compounds
• Forming nitriles from haloalkanes

  Add NaCN to a 3 carbon haloalkane with ethanol solvent to form a 4 carbon nitrile nucleophilic substitution

  
• Forming (hydroxy)nitriles from aldehydes and ketones

  Add HCN in a nucleophilic addition reaction to form a hydroxynitrile(or use NaCN/H2SO4 as it is less poisonous and increases reaction rate)

  
• Why is ethanol solvent used rather than water in the formation of nitriles from haloalkanes

  Water as a solvent will cause further substitution of the halogen to form an alcohol whereas ethanol won't
• Reduction of nitriles (to an amine)

  React nitrile with 2H2 in the presence of a Nickel catalyst to form an amine

  
• Hydrolysis of nitriles (to a carboxylic acid)

  Nitriles form carboxylic acids and anammonium salt when heated with dilute aqueous acid(HCl (aq)) with the addition of water(hydrolysis)

  
• Forming carbon-carbon bonds to benzene rings- alkylation

  Alkyl group is transferred in the presence of a Friedel-Crafts catalyst such as AlCl3

  
• Forming carbon-carbon bonds to benzene rings- acylation


  Benzene reacts with an acyl chloride in the presence of an AlCl3 catalyst forming a ketone