Q.Which of the following is a secondary amine?

Amine class is set by the number of carbons on N; here N has only one carbon -> primary amine.

Amines are classified by the number of carbon atoms directly attached to the nitrogen:

• 1 carbon on N -> primary (1deg)
• 2 carbons on N -> secondary (2deg)
• 3 carbons on N -> tertiary (3deg) …

Diphenylamine, $(C_6H_5)_2NH$, has 2 groups on N — a secondary amine.

Classify each amine by how many carbon/aryl groups are attached to nitrogen:

• Cyclohexylamine: $C_6H_{11}-NH_2$ — one substituent on N $\Rightarrow$ primary amine.
• Isopropylamine: $(CH_3)_2CH-NH_2$ — one substituent on N $\Rightarrow$ primary amine.
• Diphenylamine: $(C_6H_5)_2NH$ — two phenyl groups on N $\Rightarrow$ secondary amine. …

Amines are classified by carbons on N; here N has one carbon -> primary amine.

The compound CH3-C(CH3)(CH3)-NH2 is (CH3)3C-NH2, tert-butylamine. Classification of amines is by the number of carbon atoms directly bonded to NITROGEN, not by the type of carbon:

• 1° amine: N bonded to one carbon (R-NH2)
• 2° amine: N bonded to two carbons
• 3° amine: N bonded to three carbons …

Secondary amine = R2NH, so its functional group is -NH- (>NH).

Amines are classified by how many hydrogens of ammonia (NH3) are replaced by alkyl/aryl groups:

• primary amine: R-NH2 (one H replaced) → functional group -NH2
• secondary amine: R2NH (two H replaced) → functional group -NH- (>NH) …

Classify an amine by counting how many of the three bonds on nitrogen (besides the lone pair) go to carbon (alkyl/aryl) groups versus hydrogen: 3 C = tertiary, 2 C + 1 H = secondary, 1 C + 2 H = primary.

Amines are classified as primary (1 degree), secondary (2 degree) or tertiary (3 degree) according to the number of hydrogen atoms of ammonia (NH3) that have been replaced by alkyl/aryl groups.

(i) The nitrogen here is bonded to three separate ethyl-type carbon chains (three C-N bonds, no N-H bond) - this is a tertiary amine (a trialkylamine, N,N-diethylethanamine). …

Amines are classified by the number of carbon (alkyl/aryl) groups on nitrogen, not by the branching of the carbon skeleton. Here nitrogen bears only one carbon, so it is 1°.

The compound CH3-C(CH3)(CH3)-NH2 is tert-butylamine, (CH3)3C-NH2.

Classification of amines depends on how many carbon atoms are directly bonded to the nitrogen:

• 1° (primary): one C on N (R-NH2)
• 2° (secondary): two C on N (R2NH)
• 3° (tertiary): three C on N (R3N) …

Amines are classified by how many carbon groups are attached to the nitrogen, not by which carbon skeleton those groups belong to.

The amine shown, 1-aminonaphthalene, has the -NH2 group bonded to exactly one carbon (a ring carbon of the naphthalene system). The classification of an amine (1°, 2°, 3°) depends only on the number of carbon (alkyl/aryl) groups directly attached to the nitrogen atom:

• 1° amine: N bonded to 1 carbon group (R-NH2)
• 2° amine: N bonded to 2 carbon groups (R2NH) …

Classification of amines as 1°, 2°, or 3° depends on how many alkyl/aryl groups replace the hydrogens of $NH_3$ — trimethylamine, $(CH_3)_3N$, has all three hydrogens replaced by methyl groups, making it tertiary.

Amines are considered as derivatives of ammonia, $NH_3$, obtained by replacing one, two, or three hydrogen atoms by alkyl/aryl groups:

• One H replaced: primary (1°) amine, $R\text{--}NH_2$
• Two H replaced: secondary (2°) amine, $R_2NH$
• Three H replaced: tertiary (3°) amine, $R_3N$ …

Amines are classified by how many alkyl/aryl groups replace the hydrogens of ammonia; one substitution gives a primary amine, two gives a secondary amine.

Classifying by degree of substitution

Amines are derivatives of ammonia ($NH_3$) formed by replacing one, two, or three hydrogen atoms with alkyl/aryl groups:

• $CH_3NH_2$ (methanamine): only ONE hydrogen of ammonia is replaced, by a methyl group; the nitrogen is bonded to one carbon group and two hydrogens ($R-NH_2$). This makes it a primary (1°) amine. …

Amines are ammonia derivatives with one or more H atoms replaced by alkyl/aryl groups, classified as primary, secondary, or tertiary by how many H's are replaced.

Amines can be thought of as organic derivatives of ammonia (NH$_3$), formed by successively substituting its hydrogen atoms with alkyl or aryl groups:

• Primary (1°) amine: one H replaced, R–NH$_2$ (e.g. CH$_3$NH$_2$, methylamine).
• Secondary (2°) amine: two H's replaced, R$_2$NH (e.g. (CH$_3$)$_2$NH, dimethylamine); the two R groups may be the same or different.
• Tertiary (3°) amine: all three H's replaced, R$_3$N (e.g. (CH$_3$)$_3$N, trimethylamine). …

The degree (1°/2°/3°) of an amine is decided by how many of ammonia's three hydrogens are replaced by alkyl/aryl groups; triethylamine has all three replaced.

• Triethylamine, $(C_2H_5)_3N$: all three H atoms of NH3 replaced by ethyl groups → tertiary (3°) amine.
• t-Butylamine, $(CH_3)_3C\text{-}NH_2$: only one H replaced by a (bulky) tert-butyl group → this is a primary (1°) amine, despite the branching in the alkyl group — degree of the amine depends on substitution at nitrogen, not on the alkyl group's own structure. …