Understanding Amines: Structure, Properties & Types

• During allergic reactions, the immune system overreacts to foreign substances, causing airway swelling and fluid in the lungs
• Epinephrine, also known as adrenaline, is the common treatment for severe allergic reactions
• It's a hormone produced by adrenal glands, containing an amino group (-NH)
• Amines are organic compounds that contain nitrogen.

Amines

• Amines are ammonia derivatives where hydrogen atoms are replaced by alkyl groups
• Amines are classified based on the number of alkyl groups attached to the nitrogen atom:
  • Primary (1°): one alkyl group
  • Secondary (2°): two alkyl groups
  • Tertiary (3°): three alkyl groups
• Amines typically possess strong and unpleasant odors, often described as "fishy" and resembling ammonia
• Urine contains amines from protein breakdown
• Decaying tissues produce amines like putrescine (H2N(CH2)4NH2) and cadaverine (H2N(CH2)5NH2), which have amino groups at each end
• Aromatic amines are used in dye production
• Many aromatic amines are carcinogenic and must be handled carefully

Naming Amines

• IUPAC naming system adds the suffix "-amine" to the chain or ring name, removing the "-e"
• Aromatic amines with an amine group on a benzene ring are named aniline
• For secondary and tertiary amines, the base name is derived from the longest alkyl group
• The locator "N" indicates additional chains attached to the nitrogen atom
• For instance, an amine with ethyl, propyl, and butyl groups bonded to the nitrogen atom at carbon number 1 is named N-ethyl-N-propylbutan-1-amine
• Some compounds contain multiple amino groups and are called diamines; cadaverine (NH2(CH2)5NH2) is pentane-1,5-diamine

Properties of Amines

• Small amines are soluble in water
• N-C and N-H bonds are polar due to nitrogen's electronegativity
• Polarity strengthens van der Waals forces, increasing energy needed for separation
• Amines have higher melting and boiling points than corresponding hydrocarbons
• Reducing the number of N-H groups lowers boiling points

Amides

• Amides resemble esters but feature a nitrogen atom instead of oxygen next to a carbonyl group
• The amide functional group is a carbonyl group bonded to a nitrogen atom

Naming Amides

• The name of an amide has three parts: the first from the amine, the second from the acid, with the suffix -amide
• The reaction of methanamine and butanoic acid yields N-methylbutanamide

Properties of Amides

• Smaller amides are somewhat soluble in water due to -NH groups forming hydrogen bonds with water
• Increased carbon chain length decreases solubility
• Primary amides have higher melting and boiling points due to more hydrogen bonding

Reactions Involving Amines and Amides

• Amines are synthesized from alkyl halides and ammonia
• Ethanamine, a primary amine, reacts with iodoethane to produce N-ethylethanamine (secondary amine) and hydrogen iodide
• N-ethylethanamine reacts with iodoethane to form N,N-diethylethanamine (tertiary amine) and hydrogen iodide
• Amides can be synthesized from carboxylic acids with ammonia, primary, or secondary amines by condensation reaction
• Reactions are reversible where amides can be hydrolyzed in acidic or basic conditions to produce carboxylic acids and amines