1 / 11

Amines

Amines. Caffeine. Nitrogen Chemistry. Nitrogen will readily form 3 covalent bonds (each atom already has 5 v.e - ) Carbon forms 4 covalent bonds Oxygen forms 2 covalent bonds. Structure & Classification of Amines. Amines are derivatives of ammonia (NH 3 ) Functional group = NH x

jeanniet
Download Presentation

Amines

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Amines Caffeine

  2. Nitrogen Chemistry • Nitrogen will readily form 3 covalent bonds (each atom already has 5 v.e-) • Carbon forms 4 covalent bonds • Oxygen forms 2 covalent bonds

  3. Structure & Classification of Amines • Amines are derivatives of ammonia (NH3) • Functional group = NHx • Aromatic amines = aniline -->

  4. IUPAC (longest chain = alkane) Primary Alkanamine # is used to ID location of fcn’l group on alkane chain Can have diamines, etc. Secondary N-alkylalkanamine Tertiary N-alkyl-N-alkylalkanamine Multifunctional groups Amine = substituent (amino), Carboxylic acid Aldehyde Ketone Alcohol Amine Common Primary Alkylamine Secondary Alkylalkylamine Tertiary Alkylalkylalkylamine Isomers Skeletal (C atoms) Positional (NHx group) Amine Nomenclature

  5. Physical Properties of Amines • State: low MW = gases @ RT • Smell like ammonia • high MW = liquids @ RT • Bad odors • BP: alkanes<amines<alcohols • Hydrogen bonding • Water solubility • Low MW = v. soluble • High MW = soluble

  6. Amines are weak Bases • NH3 + HOH <==> NH4+ + OH- ammonium ion • CH3-NH2 + HOH <==> CH3-NH3+ + OH- methylaminemethylammonium ion methanamine • Amine Salts • Acid + amine --> Amine salt + water (protonation) • HCl + CH3-NH2 --> CH3-NH3+Cl- methylammonium chloride • Amine salt + base --> amine + salt + water (deprotonation) • CH3-NH3+Cl- + NaOH --> CH3-NH2 + NaCl + HOH

  7. Preparation of Amines • Alkylation in the presence of a base • Ammonia + alkyl halide --> 1˚ amine • NH3 + CH3Cl --> CH3NH3+Cl- + NaOH --> CH3NH2 + NaCl + HOH • The primary amine will continue to react unless it is removed as it is produced. • 1˚ amine + alkyl halide --> 2˚ amine • 2˚ amine + alkyl halide --> 3˚ amine • 3˚ amine + alkyl halide --> quaternary ammonium salt • Quaternary ammonium saltsmay be biochemically important • Ex.: choline (growth reg.) & acetylcholine (nerve impulse transmission)

  8. Heterocyclic AminesNitrogen atoms are part of a ring system Hemoglobin -pyrrole derivative Nicotine Caffeine - pyridine derivative -purine derivative

  9. Biochemically Important Amines • Neurotransmitters • Acetylcholine, norepinephrine • Dopamine, serotonin • Epinephrine • Adrenaline • Amphetamines - structurally related to adrenalin • Histamine • Responsible for effects of hay fever & pollen allergies • These effects are counteracted by antihistamines

  10. Alkaloids - plant based amines • Nicotine, caffeine, cocaine • Chocolate • Quinine, atropine • Opium • Codeine, Morphine (heroin) Theobromine - Greek (“theo” - god; “brosis” - food) The alkaloid atropine is obtained from the belladonna plant. Poppy

  11. What do you need to know? • Structural characteristics (know the functional group) • Carboxylic Acids • Esters • Phosphate Esters • Amides • Amines • Isomers; Functional group isomers • Nomenclature (the rules for naming the molecules) • Common & IUPAC • Amides: (alkylalkylamide) N-alkylalkanamide • Amines: (alkylalkylamine) N-alkylalkanamine • Physical properties (basic/simple) • pH; BP; Solubility; Flammability • Acids ~ hydrogen bonding! • Esters ~ no hydrogen bonding (a lot like ethers) • Amides: lower pH; most are solids @ RT • Amines: higher pH; most are liquids @ RT • Occurrence and uses (common) • Acids - metabolic intermediates & products; antimicrobials • Esters - flavors/fragrances; pheromones; medications • Phosphate esters • Amides - Urea; barbiturates; polyamides & polyurethanes • Amines - Biochemical; Alkaloids • Preparation (what basic reactions produce the molecules) • Acids - Oxidation of aldehydes; of alkyl benzene • Esters - Esterification (C. acid + alcohol); condensation polymerization • Amides - (amidification) Amine + C. Acid --> amide • Amines - Rxn w/ alkyl halide (in base) • Characteristic reactions of the molecules • Acids - Neutralization; Esterification; acid salts (rxn w/ SB or SA) • Esters - Ester Hydrolysis (in acid); Saponification (in base) • Amides - Hydrolysis (acidic & basic); polymerization • Amines - Protonation<==> Deprotonation

More Related