Show how m-toluidine can be converted to the following compounds, using any necessary reagents.



(a)

Verified step by step guidance

1. Step 1: Begin with m-toluidine (C6H4(CH3)(NH2)), which contains an amino group (-NH2) and a methyl group (-CH3) on the benzene ring in the meta position.
2. Step 2: Convert the amino group (-NH2) into a diazonium salt (-N2+). This is achieved by treating m-toluidine with sodium nitrite (NaNO2) and hydrochloric acid (HCl) at low temperatures (0–5°C). The reaction forms m-toluidine diazonium chloride.
3. Step 3: Replace the diazonium group (-N2+) with a cyano group (-CN) to form m-toluonitrile. This substitution is carried out using copper(I) cyanide (CuCN) in a Sandmeyer reaction. The diazonium salt reacts with CuCN to yield m-toluonitrile.
4. Step 4: Isolate and purify the m-toluonitrile product using standard organic chemistry techniques such as distillation or recrystallization.
5. Step 5: Verify the structure of m-toluonitrile using spectroscopic methods such as IR spectroscopy (to confirm the presence of the nitrile group, C≡N) and NMR spectroscopy (to confirm the positions of the substituents on the benzene ring).

Key Concepts

Amines and Their Reactivity

Amines, such as m-toluidine, are organic compounds derived from ammonia by replacing one or more hydrogen atoms with alkyl or aryl groups. They exhibit nucleophilic behavior due to the lone pair of electrons on the nitrogen atom, allowing them to participate in various reactions, including electrophilic aromatic substitution and acylation. Understanding the reactivity of amines is crucial for predicting the products of their transformations.

Electrophilic Aromatic Substitution (EAS)

Electrophilic aromatic substitution is a fundamental reaction in organic chemistry where an electrophile replaces a hydrogen atom on an aromatic ring. In the case of m-toluidine, the amino group is a strong activating group, directing incoming electrophiles to the ortho and para positions. This concept is essential for determining how m-toluidine can be modified to form various substituted aromatic compounds.

Functional Group Transformations

Functional group transformations involve converting one functional group into another through chemical reactions. In the context of m-toluidine, this may include oxidation, reduction, or substitution reactions to create desired products. Familiarity with common reagents and their effects on amines is vital for successfully planning the synthesis of the target compounds.