Module 6:Organic Synthesis - C-C Bond Formation (6.2.4)

Question 1

Formation of Nitriles from Haloalkanes

Answer 1

1. React haloalkane with NaCN or KCN in ethanol.
2. Increases C chain length.
3. Nucleophilic substitution.
4. Halogen more electronegative than C.
5. :C≡N- nucleophile attacks carbon as its slightly positively charged. (𝛿+)
6. Halogen becomes 𝛿− and breaks off by heterolytic fission.
7. C≡N substitutes halogen, halide a by product.

Question 2

Formation of Nitriles from Aldehydes/Ketones

Question 3

Reduction of Nitriles

Answer 3

1. Reduced to amines by Hydrogen and a Ni catalyst.
2. EXAMPLE: CH₃CH₂C≡N + 2H₂ ——-> CH₃CH₂NH₂
3. Propanenitrile to Propylamine.
4. Ni catalyst over the arrow.

Question 4

Hydrolysis of Nitriles

Answer 4

1. Undergo hydrolysis to form carboxylic acids.
2. CH₃CH₂CH₂C≡N + 2H₂O +HCl ——-> CH₃CH₂CH₂COOH + NH₄Cl
3. Butane nitrile to butanoic acid.