Amines

1
Chapter 15

• Amines

2
Amines

• Ammonia-like compounds
• Amines one or more hydrogens have been replaced
  by an organic R group

3
Amines

• Quaternary Ammonium ion arises when a 4th group
  is attached to the nitrogen through the lone pair

4
Amines

• Naming Amines
• Primary amines
• Name the alkyl group followed by suffix
• -amine

5
Amines

• Naming Amines
• Secondary and Tertiary amines
• If the alkyl groups are identical
• Use a prefix to indicate the number of alkyl
  groups on the N
• Name of the alkyl group
• End with the word amine
• If the alkyl groups differ
• Identify the alkyl group with the most carbons
  (parent)
• Name all other groups as N-substituents

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Amines

• Naming Amines
• Heterocyclic amines (ring structures containing
  N) complicated naming
• Aromatic Amines
• Parent is Aniline

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Amines

• Amino Acids

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Properties of Amines

• Primary and secondary amines hydrogen bond
  increased m.p. and b.p. compared to alkanes but
  lower than comparative alcohols
• Tertiary amines do not hydrogen bond lower m.p.
  and b.p.
• Unpleasant odors
• Simple amines are water soluble due to hydrogen
  bonding
• Weak Bronsted-Lowry bases
• Many of physiologically active and toxic

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Heterocyclic Nitrogen Compounds

• Heterocycle A ring that contains nitrogen or
  some other atom in addition to carbon.
• Heterocycles are common in many natural compounds
  found in plants and animals. (Table 15.2)

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Basicity of Amines

• Amines act similar to ammonia in water to form an
  ammonium ion, hence they are weakly basic.
• NH3 H2O ? NH4 OH-
• base acid conjugate
• acid

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Basicity of Amines

• The positive ions formed by addition of H to
  alkylamines are named by replacing the ending
  -amine by the ending -ammonium.

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Basicity of Amines

• Nonaromatic amines gt Ammonia gt Aromatic amines

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Amine Salts

• Amine salt is composed of an ammonium cation and
  an anion.
• The name of an amine salt is a combination of the
  names of the ions.

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Amine Salts

• Medicinal chemistry
• The formula of an amine salt is a combination of
  the amine the acid that makes the salt
• (CH3CH2CH2)2NH . HCl
• The name of the salt is a combination of the name
  of the amine and the acid that makes up the salt
• Dipropylamine hydrochloride

15
Amine Salts

• Quaternary ammonium ions have four organic groups
  bonded to the nitrogen atom. Their structures in
  solution are unaffected by changes in pH.

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Amines in Plants Alkaloids

• Alkaloid A naturally occurring,
  nitrogen-containing compound isolated from a
  plant usually basic, bitter, and poisonous. The
  bitterness and poisonous nature of alkaloids
  probably evolved to protect plants from being
  devoured by animals.

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Amines in Plants Alkaloids

• Many alkaloids are physiologically active.
• Caffeine and nicotine are stimulants.
• Others are notable as pain relievers
  (analgesics), as sleep inducers, and for the
  euphoric states they can create.

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Homework

• 15.21, 15.22, 15.23, 15.25, 15.26, 15.27, 15.28,
  15.29, 15.32, 15.34, 15.35, 15.36, 15.37, 15.38,
  15.39, 15.40, 15.41, 15.46, 15.49, 15.50, 15.51,
  15.52, 15.54, 15.55, 15.56, 15.58, 15.59, 15.60,
  15.62, 15.64