Reactions Of Amines

Question 1

Alkylation

Answer 1

Amines react with alky halides and undergoes nucleophilic substitution reaction to give a mixture of , secondary , teritiary and quartenery structure of ammonium salt

R-X+R-NH2(alc.) ——> R2NH+R3N+R4N+X-

Question 2

Acylation

Answer 2

The aliphatic and aromatic amine s react with acid chlorides,acid anhydride and ester in the presence of vase such as pyridine to form substituted amines

Examples
base
1) CH3-NH2 + CH3-CO-Cl———> CH3 -NH-CO-CH3+HCl

Methanamine ——> N- methylethanamide ( N- methylacetamide)

                                               base 2) (C2H5)2NH + CH3- CO- Cl ----------> (C2H5)2N -  CO - CH3 + HCl

N - ethylethanamine ——-> N,N-diethylethanamide

3) C6H5 NH2 + CH3 CO O CO CH3—>
C6H5 NH CO CH3—+ CH3 COOH

Aniline. Ethanoic anhydride—–> N phenylethanamide( acetanilide)

Question 3

What is the test for primary amine?

Answer 3

Carbylamine reaction or ( isocyanide test)

Question 4

Carbylamine reaction or isocyanide test

Answer 4

When aliphatic or aromatic primary amine is heated with chloroform and alcoholic potassium hydroxide it forms a foul smelling carbylamine or isocyanide this test is know as carbylamine reaction or isocyanide test , secondary and tertiary amines do not give this reaction

Eg: REFER NOTE

Question 5

What is nitrous acid?

Answer 5

By mixing sodium nitrite and HCl

Question 6

Reaction with nitrous acid

Answer 6

Aliphatic 1° amines react with nitrous acid to form alcohol with liberation of nitrogen gas ,fron the amount of nitrogen gas we can determine the amino acids and proteins

Eg;REFER NOTE

Question 7

What is meant by diazotisation?

Answer 7

Aromatic primary amines react with nitrous acid at 0 to 5° C to form aromatic diazonium salt

Question 8

What is hinsberg reagent?

Answer 8

Benzene sulphonyl chloride

C6H5SO2Cl

Question 9

What is the use of hinsberg reagent?

Answer 9

1) use to distinguish primary secondary and tertiary amine
2) to seperate mixture of amines

Question 10

How do primary amines react with benzene sulphonyl chloride?

Answer 10

Primary amines react with benzene sulphonyl chloride to form a precipitate of N- alkyl benzene sulphonamide ,which is soluble in alkali

Question 11

How do secondary amines react with benzene sulphonyl chloride?

Answer 11

secondary amines react with benzene sulphonyl chloride to form a precipitate of N,N- dialkylsulphonamide which is insoluble in alkali

Question 12

How do teritiary amines react with benzene sulphonyl chloride?

Answer 12

Teritiary amines does not react with benzene sulphonyl chloride

Question 13

Nowadays , benzene sulphonyl chloride is replaced by?

Answer 13

p- toluenesulphonyl chloride