PMT amines

• What are the structures of primary, secondary, and tertiary amines?

  They have one, two, and three alkyl groups respectively

  
• What is a quaternary ammonium ion?

  An ion with four alkyl groups attached to nitrogen
• How do you name amines?

  Using -amine or amino- prefixes
• Why are amines so reactive?

  Due to the lone pair on nitrogen and polar N-H bond
• What is the shape of amines around the nitrogen atom?

  Trigonal pyramidal with a bond angle of 107°
• What kind of intermolecular forces do amines have?

  Hydrogen bonding due to polar N-H bonds
• Are the intermolecular forces in amines stronger or weaker than in alcohols?

  Weaker, because nitrogen is less electronegative than oxygen
• How can amines act as bases?

  The lone pair on nitrogen accepts a proton

  
• When do amines act as nucleophiles?

  When they bond with an electron-deficient carbon atom
• What is the product from the basic action of an amine with water?

  Ammonium ion (RNH3⁺) and an anion

  
• What is the equation for methylamine reacting with HCl?

  RNH2 + HCl → RNH3⁺Cl^-
• What must a particular amine have to be the strongest base?

  Greatest electron density around the nitrogen atom
• What effect do alkyl groups have on electron density and base strength?

  They increase electron density around nitrogen
• Place the following in order of base strength: NH3, 1° amine, 2° amine, phenylamine.

  2° amine > 1° amine > NH3 > phenylamine
• How can primary amines form 2° and 3° amines and 4° ammonium ions?

  Through multiple substitutions with haloalkanes
• What are the problems with the method of forming amines through substitutions?

  Low yield of 1° amine due to multiple substitutions
• How would you maximize the yield of the primary amine?

  By using excess ammonia in the reaction
• What type of mechanism is the reaction of a haloalkane with a cyanide ion?

  Nucleophilic substitution mechanism
• What conditions are required for the reaction of a haloalkane with cyanide ion?

  Ethanol as a solvent to form a nitrile
• How do you convert a nitrile to a primary amine?

  By reduction using Nickel/Hydrogen catalyst
• Why is the reduction of nitriles a purer method of synthesizing amines?

  Only the primary amine can be formed
• What conditions are needed to form nitrobenzene from benzene?

  Concentrated H2SO4 and HNO3 for NO2⁺ ion
• How do you form an ammonium chloride salt from nitrobenzene?

  Reduce nitrile using Tin/HCl at room temperature
• What is the equation for the reaction of nitrobenzene to phenylamine?

  C6H5NO2 + 6[H] → C6H5NH2 + 2H2O
• What mechanism is used for forming amides from acyl chlorides and amines?

  Nucleophilic addition/elimination mechanism
• How do you draw a mechanism for the reaction of ethanoyl chloride with ethanamine?

  By illustrating nucleophilic addition/elimination steps