Question

Classify the following amines as simple/mixed; 1°, 2°, 3° and aliphatic or aromatic. (C₂H₅)₂ NH, (CH₃)₃ N, C₂H₅ – NH – CH₃,

Answer 1

Compound	Simple/mixed	Type	Aliphatic/Aromatic amine
(1) (C2H5)2 NH	Simple	Secondary (2°) amine	Aliphatic
(2) (CH3)3 N	Mixed	Tertiary (3°) amine	Aliphatic
(3) C2H5 - NH - CH3	Mixed	Secondary (2°) amine	Aliphatic
(4) C6H5 - NH2	Simple	Primary (1°) amine	Aromatic
	Simple	Primary (1°) amine	Aliphatic
	Simple	Secondary (2°) amine	Aromatic
	Mixed	Primary (1°) amine	Aliphatic
	Mixed	Tertiary (3°) amine	Aromatic
	Mixed	Tertiary (3°) amine	Aromatic

(A) Common Names : Rules

1. According to common naming system, the amines are named as alkylamines. 

2. The common name of a primary amine is obtained by writing the name of the alkyl group followed by the word ‘amine’.

Example : CH₃ – NH₂ : methyl-amine

3. The simple {symmetrical) secondary and tertiary amines are written by adding prefix ‘di- (for presence of two alkyl groups) and ‘tri’- (for presence of three alkyl groups) respectively to the name of alkyl groups.

Examples: (i) CH₃ – NH – CH₃ dimethylamine, 

(ii) (C₂H₅)₃ N triethylamine

4. The mixed (or unsymmetrical) secondary and tertiary amines are given names by writing the names of alkyl groups in alphabetical order, followed by the word ‘amine’.

Example : CH₃ – CH₂ – NH – CH₃ ethyhnethylamine

(B) IUPAC names : Rules

1. According to IUPAC system of nomenclature of amines, aliphatic amines are named as alkanarnines. 

2. The name of the amine is obtained by replacing the suffix ‘e’ from parent alkane’s name by ‘amine’. 

3. The position of the amino group is indicated by the lowest possible locant. 

Example :

4. In case of secondary and tertiary amines, the largest alkyl group is considered to be the parent alkane and other alkyl groups are written as Nsubstituents.

Example : ClH₅NH – CH₃N – Methylethanamine

5. A complete name of amine is written as one word.