Halogenalkanes

• Halogenoalkanes

  Reactive compounds useful in organic synthesis, can be used as refrigerants and solvents but some are damaging to the ozone layer
• Nucleophilic substitution with CN-


  1. Halogenoalkane + CN-

  2. Removal of halide

  3. Replacement with nitrile group
• Nucleophilic substitution with NH3


  1. Halogenoalkane + NH3

  2. Removal of halide

  3. Replacement with primary amine

  4. Amine can act as nucleophile for further substitution
• Pentanenitrile can be made by reaction of bromobutane with potassium cyanide
• Three methods to produce ethanol: fermentation, nucleophilic substitution of bromoethane with OH-, and steam hydration of ethene
• Reflux


  Heating and simultaneously condensing using a vertical Liebig condenser
• Nucleophilic substitution of bromoethane with OH- is not used industrially to make ethanol because bromoethane is an expensive starting material and elimination can also occur
• Either with skeletal formula or displayed formula just work carefully to make sure you don't miss any hydrogens off in the case of the displayed formula and in the zigzags always just go back through and count the number of carbon atoms it's easy to sometimes make a mistake on zigzags
• Mechanism with ammonia

  1. Lone pair on nucleophile attracted to delta positive carbon

  2. Bond breaking

  3. Intermediate with positive charge on ammonia

  4. Ammonia acts as base to remove proton

  5. Final amine product