Question 24.1: Many familiar substances are organic compounds. Some example...
Many familiar substances are organic compounds. Some examples include aspartame, the artificial sweetener in the sugar substitute Equal and in many diet sodas; salicylic acid, found in some acne medicines and wart-removal treatments; and amphetamine, a stimulant used to treat narcolepsy, attention-deficit hyperactivity disorder (\text{ADHD}), and obesity. Identify the functional group(s) in each molecule:
Strategy Look for and identify the combinations of atoms shown in Table 24.2.
Setup (a) From right to left, aspartame contains a \text{—COOH} group, an \text{—NH}_2 group, a \text{—CONHR} group, and a \text{—COOR} group:
(b) Salicylic acid contains an \text{—OH} group and a \text{—COOH} group:
(c) Amphetamine contains an \text{—NH}_2 group:
| TA B L E 2 4 . 2 General Formulas for Select Classes of Organic Compounds | |||
| Class | General formula | Structure | Functional group^{(1)} |
| Alcohol | ROH |  |
Hydroxy group |
| Carboxylic acid | RCOOH |  |
Carboxy group |
| Ester^* | RCOOR′ |  |
Ester group |
| Aldehyde | RCHO |  |
Carbonyl group |
| Ketone | RCOR′ |  |
Carbonyl group |
| Amine^† | RNH_2 |  |
Amino group (primary, 1°) |
| Amine | RNR′H |  |
Amino group (secondary, 2°) |
| Amine | RNR′R″ |  |
Amino group (tertiary, 3°) |
| Amide | RCONH_2 |  |
Amide group (primary, 1°) |
| Amide | RCONR′H |  |
Amide group (secondary, 2°) |
| Amide | RCONR′R″ |  |
Amide group (tertiary, 3°) |
| ^*R′ represents a second alkyl group that may or may not be identical to the first alkyl group R. Likewise, R″ represents a third alkyl group that may or may not be identical to R or R′. | |||
| ^†The designations 1°, 2°, and 3° refer to how many R groups are bonded to the N atom. | |||
| ^{(1)}Student Annotation: Some functional groups have special names and some do not. | |||
(a) From right to left, aspartame contains a carboxy group, an amino group, an amide group, and a \text{—COOR} (ester) group.
(b) Salicylic acid contains a hydroxy group and a carboxy group.
(c) Amphetamine contains an amino group