Chapter 28 - Carbon - Carbon bond formation

Question 1

How can you form nitriles from haloalkanes?

Answer 1

a. Nitriles can be formed by reacting haloalkanes with sodium cyanide, NaCN, or potassium cyanide, KCN, in ethanol. Through a nucleophilic substitution reaction.
b. In this reaction the carbon length of the carbon chain is increased.

Question 2

How can you produce nitriles from aldehydes and ketones?

Answer 2

a. Aldehydes and ketones will react with hydrogen cyanide in a nucleophilic addition reaction.
b. This reaction forms a carbon-carbon bond, thus increasing the number of carbon atoms in the molecule.
c. The product is known as a hydroxynitrile.
d. Hydrogen cyanide is far too poisonous to use, and an increased reaction rate can be obtained in the presence of cyanide ions.
e. A mixture of sodium cyanide and sulfuric acid is used, which improves safety and increases reaction rate.

Question 3

Describe the reduction of nitriles.

Answer 3

a. Nitriles can be reduced to amines by reacting with hydrogen in the presence of a nickel catalyst.
b. 2moles of Hydrogen gas and a Ni catalyst, forms an amine.

Question 4

Describe the hydrolysis of nitriles.

Answer 4

a. Nitriles undergo hydrolysis to form carboxylic acids by heating with dilute aqueous acid, for example, HCl(aq).
b. 2 moles of H20, and HCl to produce carboxylic acid and ammonium chloride.