Amines – Organic Chemistry – list of solved problems

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Written by J.A Dobado | Last Updated on April 22, 2024

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Amines – list of problems

Problem 1)

Classify the following compounds (a-h) as primary amines, secondary amines, tertiary amines and quaternary ammonium salts, as appropriate.

1036

Problem 2)

Complete the following Gabriel syntheses (a-c).

1037

Problem 3)

Order in increasing order of basicity the following compounds, justifying the results.

1038

Problem 4)

a) Order from higher to lower basicity the following amines, justifying the result.

  • (I) Methylamine
  • (II) Aniline
  • (III) p-Chloroaniline
  • (IV) Trimethylamine
  • (V) Tetramethylammonium bromide

b) Which amine in the series will be most effective as a nucleophile?

Problem 5)

Describe a simple method to obtain N-methylbenzamide from methylamine.

Problem 6)

When pentyl amine is treated with nitrous acid in the presence of hydrochloric acid, nitrogen is observed to be given off and a mixture of 5 products is formed. Justify the result.

Problem 7)

An amine of molecular formula C6H15N reacts with one mole of CH3I followed by hot wet silver oxide to give but-1-ene. Deduce which amine it is.

Problem 8)

An aqueous solution of sodium hydroxide and benzenesulfonyl chloride is reacted with an amine of molecular formula C4H11N to give a precipitate. From this result deduce the structure of the amine.

Problem 9)

Complete the following reactions (a-d):

1039

Problem 10)

Normally, the alkylation of a primary or secondary amine does not stop at monoalkylation because the product reacts back with the excess of the amine used as a reactant. Write all the products for the alkylation reaction between ethylamine and methyl iodide.

Problem 11)

Justify whether amines (a-f) can be obtained by a Gabriel synthesis.

1040

Problem 12)

What reagents (a-f) are needed to obtain the following compounds (I-III) by the Mannich reaction?

1041

  • a) CH3CH2NHCH3 + CH2O + HCOPh
  • b) (CH3)3N + CH3CH2COPh
  • c) CH3CH2NHCH3 + CH2O + CH3CH2COPh
  • d) CH3CH2CH2N(CH3CH2)CH3 + HCOPh
  • e) CH3NH2 + (CH3)2CHCOPh
  • f) CH3CH2N(CH3)2 + CH2O + HCOPh
  • g) (CH3)2NH + (CH3)2CHCOPh
  • h) CH3CH2N(CH3)2 + CH3CH2COPh
  • i) (CH3)2NH + CH3CH2COPh
  • j) CH3CH2N(CH3)2 + CH2O + CH3COPh
  • k) CH3CH2CH2N(CH3)2 + HCOPh
  • l) (CH3)2NH + CH2O+ CH3COPh
  • m) CH3NH2 + CH2O + CH3CH2COPh
  • n) (CH3)3N + CH2O + CH3COPh
  • o) (CH3CH2)2NCH3 + CH2O + HCOPh
  • p) (CH3)2NH + CH2O+ CH3CH2COPh
  • q) CH3CH2NHCH3 + (CH3)2CHCOPh
  • r) CH3CH2CH2NHCH3 + HCOPh

Problem 13)

Write which intermediate and major product is obtained in the following sequences of reactions ending with Hofmann elimination.

1042

Problem 14)

Classify the following compounds (a-h) as primary amines, secondary amines, tertiary amines and quaternary aminium salts.

1043

Problem 15)

Complete the following acid-base reactions of amines (a-d).

1044

Problem 16)

Write the major product obtained in the second Hofmann elimination steps.

1045

Problem 17)

Indicate which compounds (a-u) you would use in a Mannich reaction to obtain the compounds (I-III) in the box.

1046

Problem 18)

Complete the following Gabriel syntheses (a-c).

1047

Problem 19)

What amines are obtained with the starting reagents (a-c), using Gabriel synthesis?

1048

Problem 20)

Draw the structure of the compounds obtained when the following amines are treated with sodium nitrite in acidic medium.

1049

Problem 21)

How could the following transformations be carried out?

1050

Problem 22)

What products would be obtained by Hofmann degradation of the following amines?

1051

Problem 23)

Suggest a preparation of benzylamine using Gabriel synthesis.