Carboxylic Acids Esters Amines and Amides Carboxylic Acids

Carboxylic Acids, Esters, Amines and Amides Carboxylic Acids Properties of Carboxylic Acids Esterification and Hydrolysis 1

Carboxyl Group Carboxylic acids contain the carboxyl group on carbon 1. O CH 3 — C—OH = CH 3—COOH carboxyl group 2

Naming Carboxylic Acids Formula IUPAC alkan -oic acid Common prefix – ic acid HCOOH methanoic acid formic acid CH 3 COOH ethanoic acid acetic acid CH 3 CH 2 COOH propanoic acid propionic acid CH 3 CH 2 COOH butanoic acid butyric acid 3

Naming Rules • Identify longest chain • (IUPAC) Number carboxyl carbon as 1 • (Common) Assign , , to carbon atoms adjacent to carboxyl carbon CH 3 | CH 3 — CH—CH 2 —COOH IUPAC 3 -methylbutanoic acid Common -methylbutryic acid 4

Learning Check CA 1 Give IUPAC and common names: A. CH 3 COOH CH 3 | B. CH 3 CHCOOH 5

Solution CA 1 A. CH 3 COOH ethanoic acid; acetic acid CH 3 | B. CH 3 CHCOOH 2 -methylpropanoic acid; -methylpropionic acid 6

Properties • Carboxylic acids are weak acids CH 3 COOH + H 2 O • Neutralized by a base CH 3 COOH + Na. OH CH 3 COO– + H 3 O+ CH 3 COO– Na+ + H 2 O 7

Esters In and ester, the H in the carboxyl group is replaced with an alkyl group O CH 3 — C—O —CH 3 = CH 3—COO —CH 3 ester group 8

Esters in Plants Esters give flowers and fruits their pleasant fragances and flavors. 9

Naming Esters • Name the alkyl from the alcohol –O • Name the acid with the C=O with –ate acid alcohol O methyl CH 3 — C—O —CH 3 Ethanoate methyl ethanoate (IUPAC) (acetate) methyl acetate (common) 10

Some Esters and Their Names Flavor/Odor Raspberries HCOOCH 2 CH 3 ethyl methanoate (IUPAC) ethyl formate (common) Pineapples CH 3 CH 2 COOCH 2 CH 3 ethyl butanoate (IUPAC) ethyl butyrate (common) 11

Learning Check CA 2 Give the IUPAC and common names of the following compound, which is responsible for the flavor and odor of pears. O CH 3 — C—O —CH 2 CH 3 12

Solution CA 2 O propyl CH 3 — C—O —CH 2 CH 3 propyl ethanoate (IUPAC) propyl acetate (common) 13

Learning Check CA 3 Draw the structure of the following compounds: A. 3 -bromobutanoic acid B. Ethyl propionoate 14

Solution CA 3 A. 3 -bromobutanoic acid Br | CH 3 CHCH 2 COOH B. Ethyl propionoate O CH 3 CH 2 COCH 2 CH 3 CH 2 COOCH 2 CH 3 15

Esterification • Reaction of a carboxylic acid and alcohol • Acid catalyst O H+ CH 3 — C—OH + HO—CH 2 CH 3 O CH 3 — C—O—CH 2 CH 3 + H 2 O 16

Hydrolysis • Esters react with water and acid catalyst • Split into carboxylic acid and alcohol O H+ H — C—O—CH 2 CH 3 + H 2 O O H — C—OH + HO—CH 2 CH 3 17

Saponification • Esters react with a bases • Produce the salt of the carboxylic acid and alcohol O CH 3 C—OCH 2 CH 3 + Na. OH O CH 3 C—O– Na+ + HOCH 2 CH 3 salt of carboxylic acid 18

Learning Check CA 4 Write the equation for the reaction of propionic acid and methyl alcohol in the presence of an acid catalyst. 19

Solution CA 4 O H+ CH 3 CH 2 COH + HOCH 3 O CH 3 CH 2 COCH 3 + H 2 O 20

Learning Check CA 5 What are the organic products when methylacetate reacts with A. Water and an acid catalyst? B. KOH? 21

Solution CA 5 A. O CH 3 COH + HOCH 3 O B. CH 3 CO– K+ + HOCH 3 22