Orgo C 2 Amines and Amides Theory 2nd P Review

These flashcards cover key concepts related to amines and amides, their properties, classifications, naming conventions, and applications.

What are amines?

Amines are organic derivatives of ammonia (NH₃) where one or more hydrogens are replaced by alkyl or aryl groups.

Why are amines basic?

Because nitrogen has a lone pair capable of accepting protons.

What is the biological importance of amines?

They appear in amino acids, proteins, neurotransmitters, and hormones like adrenaline.

What is the molecular structure of amines?

Amines have a pyramidal, sp³-hybridized nitrogen with one lone pair.

How do amines behave in acid-base reactions?

Amines can act as Lewis bases, Brønsted–Lowry bases, and nucleophiles.

How do amines form hydrogen bonds?

They form weaker hydrogen bonds than alcohols because N–H is less polar than O–H.

How do the boiling points of amines compare to other compounds?

Amines have higher boiling points than nonpolar molecules of similar mass but lower than alcohols.

What factors affect the solubility of amines?

Smaller amines are soluble in water; solubility decreases with higher molar mass, with primary amines being most soluble.

Why do some amines smell bad?

Certain amines (like cadaverine) produced from protein degradation have strong unpleasant odors.

How are amines classified?

Amines are classified as primary (1 alkyl group), secondary (2 alkyl groups), or tertiary (3 alkyl groups).

What is the first rule for naming amines?

Name the alkyl group + 'amine' (e.g., methylamine). Use di-, tri- for repeated groups.

What is the second rule for naming amines?

When substituents differ, use N- to indicate attachment to nitrogen.

What is the third rule for naming amines?

If –NH₂ is a substituent → use amino- with a locator.

What is the fourth rule for naming amines?

When N atoms are part of the main chain → use aza in the name.

Can you give examples of cyclic and aromatic amines?

Examples include cyclohexylamine, aniline, piperidine.

Why are aromatic amines considered weaker bases?

The lone pair on nitrogen is delocalized into the aromatic ring by resonance.

How are amines synthesized from alkyl halides?

Ammonia performs nucleophilic substitution to form amines.

What is the result of reducing nitriles?

Nitriles reduce to primary amines.

How are amides reduced to amines?

Amides reduce to amines using LiAlH₄.

What is the Hofmann rearrangement?

Amides react with Br₂ + NaOH to form amines with one fewer carbon.

What happens when amines react with alkyl halides?

Amines undergo SN2 alkylation unless the halide is tertiary.

What do secondary amines form when reacted with nitrous acid?

They form N-nitrosamines, which can be found in cooked meats and are potentially carcinogenic.

What do tertiary amines form when reacted with nitrous acid?

They form nitrosoammonium salts.

What are the nitrogenous bases found in DNA/RNA?

Adenine, Guanine, Cytosine, Thymine (DNA), and Uracil (RNA).

What properties do nitrogenous bases have?

They are aromatic, planar, and stabilize nucleic acids through hydrophobic interactions.

What are neurotransmitters?

Chemical messengers that transmit signals between neurons and cells.

How are neurotransmitters classified?

They can be functionally classified as excitatory (e.g., epinephrine, norepinephrine) or inhibitory (e.g., serotonin, GABA).

What are alkaloids?

Nitrogenous plant compounds with strong biological effects and often high toxicity.

Where are alkaloids commonly found?

In roots, leaves, bark, fruits, and seeds.

Can you name some examples of alkaloids?

Morphine, cocaine, quinine, nicotine, caffeine.

What are the industrial applications of amines?

Used in plastics, dyes, lubricants, cosmetics, textiles, herbicides, cleaning products, fabric softeners, and hydrocarbon purification.

What are amides?

Amides are derivatives of carboxylic acids where the –OH is replaced by –NH₂.

What is the functional group of amides?

R–CO–NH₂.

How do the solubility properties of amides compare?

Lower members are soluble in water and alcohol; solubility decreases with molar mass.

What is the physical state of amides?

All amides are solid crystalline compounds except formamide, which is liquid.

What can be said about the polarity of the amide group?

Amide groups are highly polar.

Why is rotation around the C–N bond restricted in amides?

The partial ionic/dipolar structure restricts rotation around the C–N bond.

Why is the restricted rotation in amides significant?

It affects the secondary structure of proteins because peptide bonds behave like partial double bonds.

Can amides form hydrogen bonds?

Primary and secondary amides can form hydrogen bonds; tertiary cannot (no N–H).

What are the melting and boiling points of amides like?

Amides have high melting and boiling points.

What is the basicity of amides?

Amides are extremely weak bases and essentially neutral because resonance withdraws electron density from nitrogen.

How are amides classified?

They can be classified as primary, secondary, or tertiary depending on substitution on nitrogen.

What is the naming convention for amides?

Replace the carboxylic acid ending –oic with –amide.

How are substituted amides named?

Use N- to indicate groups attached to nitrogen.

How are amides synthesized from acids?

Carboxylic acid + ammonia → ammonium salt → amide upon heating.

How do amides undergo acid hydrolysis?

Amides + acid + heat → carboxylic acid.

What occurs during base hydrolysis of amides?

Amides with strong base + heat → carboxylate salt.

What happens when amides react with alcohols?

Amides react with alcohols to form esters + ammonia.

How are amides reduced with LiAlH₄?

Amides convert to amines without carbon loss.

What is the Hofmann transposition?

Primary amides treated with Br₂ + NaOH produce amines with one carbon less.

What pharmaceutical uses do amides have?

They are used in anesthetic production.

How are amides utilized in polymer chemistry?

Nylon contains amide linkages.

What is the biological importance of amides?

Amides form peptide bonds that link amino acids in proteins.

What are some industrial uses of amides?

Used as foaming agents; acrylamides are used in paper, metal extraction, textiles, cooling processes, and synthesis of other amides.