Transcript Ch. 16: Solutions - Quynh Nguyen Official Website
Ch. 14: Carboxylic Acids, Esters, Amines and Amides
Chem 20 El Camino College 1
H 3 C O Carboxylic Acids, Esters, Amines O H CH 3 O H 3 C O H 3 C H 3 C N amine CH 3 carboxylic acid ester O C OH carboxyl group 2
Naming Carboxylic Acids Name the longest carbon chain containing the carboxyl group.
Use the suffix “oic acid” # the chain to give the carboxyl gp the lowest # Give the location and name of other substituents in alphabetical order, using numbers, hyphens, and commas between numbers 3
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Name These O O C H OH H 3 C methanoic acid (formic acid) C OH ethanoic acid (acetic acid) O C H 3 CH 2 C OH propanoic acid O OH 3-methylpentanoic acid 5
Benzoic Acid Benzoic acid is an important carboxylic acid O O O H C C OH HC C OH OH HC CH C H 6
Carboxylic Acid Properties Carboxylic acids are extremely polar They have higher boiling pts than alcohols, ketones, and aldehydes of similar mass propanal, bp = 49 o C 1-propanol, bp = 97 o C acetic acid, bp = 118 o C Carboxylic acids with 4 C or less are water soluble 7
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Esterification Carboxylic acids react with alcohols in the presence of heat and acid (H + ) to form esters and water The OH comes off the carboxylic acid, and the H comes off the alcohol A new bond forms to make the ester O O O H + CH 2 CH 3 H 3 C O H CH 2 CH 3 H 3 C O + H 2 O 10
H O OH Draw the Ester Product O H + , heat + H O CH 3 H O O O CH 3 OH + H O CH 2 CH 3 H + , heat O CH 2 CH 3 O O H + , heat OH + H O CH 3 CH 3 O 11
Naming Esters Name the the part that came from an alcohol (directly connected to an oxygen) first, use “yl” Then name the part that came from a carboxylic acid, use the “oate” suffix O O O C H 3 C O methyl ethanoate CH 3 H 3 CH 2 C C O methyl propanoate CH 3 C H 3 CH 2 C O ethyl propanoate CH 2 CH 3 12
Properties of Esters The scents of many flowers and fruits are esters 13
Types of Amines Amines are classified as primary (1 o ), secondary (2 o ), or tertiary (3 o ) In 1 o amines, the N is attached to 1 carbon In 2 o amines, the N is attached to 2 carbons In 3 o amines, the N is attached to 3 carbons N H H ammonia H N H 3 C H 1 o amine H N H 3 C H 3 C 2 o amine H N H 3 C H 3 C 3 o amine CH 2 CH 3 14
Naming of Amines Name the carbon attachments in alphabetical order, use the word “amine” Use di- and tri- for identical substituents H 3 C H N H methylamine H 3 C H 3 C N H dimethylamine H 3 C H 3 C N CH 2 CH 3 ethyldimethylamine 15
Properties of Amines Amines tend to be bad-smelling compounds Amines are polar, they have relatively high boiling points Small amines are water soluble.
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Amide Amides are derivative of carboxylic acids, in which a nitrogen group replaces the hydroxyl group. Amide is formed when a salt of carboxylic with ammonia or amine is heated; a molecule of water is eliminated.
Amide can be hydrolyzed back to carboxylic acid and ammonium salt in acidic solution, or to a salt of carboxylic acid and ammonia or amine in basic solution.
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