Question

Which of the following is \(1^{\circ}\) amine? (A) Nc1ccccc1 (B) CC(C)(C)N (C) \(\mathrm{CH}_{3}-\mathrm{NH}_{2}\) (D) \(\mathrm{CH}_{3} \mathrm{CONH}_{2}\)

Short answer

The correct answer is Option (C) \(\mathrm{CH}_{3}-\mathrm{NH}_{2}\), which is a primary (1°) amine with the nitrogen atom attached to only one alkyl group.

Step-by-step solution

Option A

We are given a SMILES notation for the compound in Option (A): "Nc1ccccc1". This notation represents aniline, with a nitrogen atom (N) bonded directly to the cyclic aromatic structure (c1ccccc1). Although nitrogen is bound to the aromatic ring, which is an alkyl group, this compound is considered an aryl amine and not a primary amine because nitrogen is bonded to an aromatic ring, not an alkyl group.

Option B

We are given a SMILES notation for the compound in Option (B): "CC(C)(C)N". This notation represents a nitrogen atom (N) attached to a carbon (C) atom, which is itself connected to three other carbon atoms (C)(C)(C). This means that the nitrogen atom is attached to one carbon atom, and the remaining carbon atoms are attached to each other. This is a tertiary (3°) amine because the nitrogen atom is attached to three alkyl groups.

Option C

Option (C) is given by the chemical formula: \(\mathrm{CH}_{3}-\mathrm{NH}_{2}\). We can see that the nitrogen atom (N) is attached to one carbon atom (CH3) group and also bonded to two hydrogen (H) atoms. In this case, the nitrogen atom is attached to one alkyl group (CH3). Therefore, this is a primary (1°) amine.

Option D

Option (D) is given by the chemical formula: \(\mathrm{CH}_{3} \mathrm{CONH}_{2}\). The nitrogen atom (N) is in an amide functional group and not an amine. Based on the analysis above, Option (C) is the correct answer, because it represents a primary (1°) amine with the nitrogen atom attached to only one alkyl group.