Sample Questions

1. Classify each of the following amines as: aliphatic, aromatic, primary, secondary, and/or tertiary.
   
   
   
   
2. Provide a name for the amines represented by structures a, b, c, e and f in problem 1.
   
   
3. Provide the structure of the compound corresponding to each name:
   
   
   1. 2-(ethylamino)cyclohexanol
   2. meta-dimethylaminophenol
   3. ethyl para-dimethylaminobenzoate
   4. N-benzyl-N-isopropyl-2-pentanamine
   
   
   
4. Show how the following amines could be prepared by reduction of an amide or nitrile with LiAlH₄:
   
   
   
   
5. Show how the following amines could be prepared from an aldehyde or ketone and ammonia or amine by reduction alkylation/amination:
   
   
   
   
6. Rank the following amines in order of increasing base strength, with 1 = strongest base:
   
   
   
   
7. Show how to complete the following synthetic sequence:
   
   
   
   
8. Show how to convert the indicated starting material to the given product:
   
   
   
   

1. Aliphatic amines have a sp³ C to N bond, while aromatic amines have the N connected to a sp² C in an aromatic ring. Primary amines have 1 carbon group connected to N; secondary amines have 2 carbon groups bonded to N; and tertiary amines have three carbon groups connected to N.
   
   1. tertiary and aliphatic
   2. secondary and aliphatic
   3. secondary and aromatic (Yes, it also has an aliphatic portion, but the aromatic portion has a larger effect on basicity and chemical reactions.)
   4. secondary and aliphatic
   5. primary and aliphatic
   6. secondary and aliphatic
   
   
   
2. Omit d because we did not discuss how to name heterocyclic amines.
   1. N,N-dimethylcyclopentanamine
   2. N-methyl-2-phenylethanamine
   3. N-sec-butylaniline
   4. omit
   5. 2,2-dimethyl-1-propanamine
   6. N-methyl-2-butanamine
   
   
   
3. The corresponding structures are:
   
   
   
   
   
   
   
   
   
4. Reduction of an amide converts the C=O to a CH₂ group.
   Reduction of a nitrile can only produce an amine of the type R-CH₂-NH₂:
   
   
   
   
   
   
   
   
   
   
5. There are as many different ways to make the amine by reductive amination of the carbonyl compound as there are different C-N bonds in the amine.
   
   
   
   
   
   
   
   
6. All aliphatic amines are stronger bases than NH₃ and aromatic amines are weaker bases than NH₃. The strongest type base is a secondary aliphatic amine; primary and tertiary aliphatic amines are both weaker than secondary amines in water and about equal in base strength to each other. Aromatic amines with electron withdrawing groups on the aromatic ring are weaker bases than aniline itself. So the ranking, with 1 = strongest base is:
   
   
   
   
7. The missing reagents have been filled in:
   
   
   
   
8. The reagents and intermediate compounds formed in each synthesis are shown below: