Chapter 15

 Amines  -derive from ammonia  -one or more of the hydrogen atoms have been replaced by an organic group  -pyramidal in structure  -1° amine indicates 1 H replaced  -2° amine indicates 2 H’s replaced  -3° amine indicates 3 H’s replaced  The N atom is more electronegative than the H so the N-H bond is polar

 Amines  amines can bond to each other through hydrogen bonding and can also bond to water molecules  1° amines have higher boiling points than alkanes but lower boiling points than alcohols of similar molar mass  3° amines cannot bond to other amines because there is no H available to bond  3° amines have much lower boiling point than 1° and 2° amines of similar molar masses

 Amines  H bonds between amines not as strong as those in alcohols because the N is not as electronegative as the O.  1° and 2° amines have a lower boiling point than alcohols  All can form H bonds with water at the N  Small amines are soluble in water (6 carbons or less)  Solubility decreases as the carbon chain increases

 Amines- IUPAC  1. Determine the name of the parent compound (the longest continuous carbon chain containing the amine group)  2. Replace the ­–e ending from the alkane parent with –amine Ex. Ethane becomes ethanamine  3. Number the parent chain so that the carbon with the amine group has the lowest number  4. Name and number any substituents and add them as prefixes

 Example 2-pentanamine  For 2° and 3° amines, the prefix N-alkyl is added (just add the letter N)  Example N,N-Dimethylpropanamine

 A simple benzene ring with an amine is benzenamine (aniline)  See pg 499 with methyl group  If other groups are attached to the N group, use the letter N- followed by the name of the group N-methyl-1-phenyl-2-propanamine

 Amines- Common names  -used for simple amines  -use the common names of alkyl groups bonded to the amine and the ending –amine  -list alphabetically if multiple Dimethyl amine Ethylmethylamine

 Amphetamines (benzedine, methadrine)  -stimulates the central nervous system, elevate blood pressure and pulse rate, decrease fatigue  -used to treat depression and epilepsy  -found in diet pills (decrease appetite)  -controlled federally because excessive use can cause mental illness and paranoia  Analgesics (demerol)- pain relief  Anesthetics (novocaine)- pain blocker

 Ephedrine  -decongestant in cough syrup and nasal spray  -sales of ephedrine and pseudoephedrine are now behind the counter  -pharm. companies replacing these with phenylephrine

 Preparation of amines  In a lab setting, they are prepared by reducing amides into a nitro compound.  1° amines are created by reducing a nitro compound with a reducing agent  Ex. Nitrobenzene is reduced to aniline The symbol [H] is often used to show that any reduction agent can be used.

 1°, 2°, 3° amines are produced when amides are reduced  If the N on the amide has 2 hydrogen atoms, a 1° amine is produced  If there is 1 H and 1 organic compound, a 2° amine is produced  If both are organic compounds, a 3° amine is produced See page 503 for 3 different reactions

 Basicity  When dissolved in water, an amine will accept an H + ion and become a weak base.  The lone pair from the N bonds with the H + ion making an alkylammonium ion. Hydroxide ions are also produced.  Creates a base solution. You do not need to know the reaction. You need to know why amines act as bases.

 -Formed from the reaction between a carboxylic acid derivative and either ammonia or an amine.  -Composed of a carbonyl group (from the carboxylic acid) and an amino group (from the ammonia or amine)  Amide bond- bond between the carbonyl carbon and the N that contains the amine or ammonia

 -Most are solid at room temp.  -very high boiling points (due to strong H bonds between amides)  -simple amides are soluble in water (due to strong H bonds between amides)  -cannot become basic like amines (do not accept H + in water)  -there is a strong attraction between the O of the carbonyl group and the lone pair of the N which does not allow it to hold the H + (this attraction creates a resonance hybrid)

 Amides  Both IUPAC and Common come from the IUPAC and Common names of the carboxylic acids from which they are made.  -Remove –ic acid ending from the common name or –oic acid of IUPAC name of carboxylic acid  -Replace with –amide Propanamide N-Propylbutanamide

 See table 15.4 for IUPAC to Common comparisons  Substituents on the N are placed as prefixes  -indicated by N- followed by the substituent name  -no spaces between prefix and amide name

 Barbiturates (barbital)  -“downers”  -used as sedatives, anticonvulsants for epileptics, brain disorders  Acetaminophen  -used in place of aspirin  -found in Tylenol  -relieves pain, reduces fever  Phenacetin  -pain reliever created in 1887  -banned in 1083 due to cause of kidney damage and blood disorders

 Preparation of Amides  -prepared from carboxylic acid derivative (either acid chlorides or acid anhydrides)  Recall: Acid chlorides are made from carboxylic acids that react with a reagent like PCl 5  Acid chlorides react rapidly with ammonia or amines  2 moles of ammonia or amines needed in a reaction

 Type of reaction- Acyl group transfer reaction  Acyl group- found on the acid chloride  -transferred from the Cl to the N of one of the ammonia/ amine molecules  -the 2 nd reacts with the HCl that forms from the transfer to create ammonium chloride or alkyl-ammonium chloride See reaction page 513

 The reaction between acid anhydride and 2 moles of ammonia/ amine is also an acyl group transfer reaction.  See reaction page 514

 Commercial Amide  -aspartame  -artificial sweetener  -made from 2 amino acids (aspartic acid and phenylalanine) joined by an amide bond