Name the following derivatives of benzene:

SOLUTION:

Molecule 1.

1. Main chain: benzene

2. Numbering: the substituents must take the minor locants, and in addition, the minor locants are assigned to the groups that come before them in alphabetical order (ethyl before methyl)

3. Substituents: 1,2-ethyl and 3-methyl.

4. Name: 1,2-Diethyl-3-methylbenzene

Molecule 2.

1. Main chain: benzene

2. Numbering: the substituents must take the minor locators.

3. Substituents: methyls in position 1,2,3 .

4. Name: 1,2,3-Trimethylbenzene

Molecule 3.

1. Main chain: benzene

2. Numbering: the substituents must take the minor locators.

3. Substituents: methyls in position 1,2,4 .

4. Name: 1,2,4-Trimethylbenzene

The ring is numbered so that the substituents take the lowest locants. In the event of a tie, the alphabetical order is taken into account.

Molecule 4.

1. Main chain: benzene
2. Numbering: start with a methyl and number in any direction.
3. Substituents: methyls at 1,3,5 .
4. Name: 1,3,5-Trimethylbenzene

Molecule 5.

1. Main chain: benzene
2. Numbering: the numbering starts at the chlorine (it goes alphabetically first) and continues along the shortest path towards the hydroxyl.
3. Substituents: chlorine in position 1 and hydroxy in position 3 (meta position)
4. Name: 1-Chloro-3-hydroxybenzene ( m-Chlorohydroxybenzene)

Molecule 6.

1. Main chain: benzene
2. Numbering: Numbering starts on the bromine (alphabetical preference)
3. Substituents: bromo in position 1 and nitro in position 3 (ortho position)
4. Name: 1-Bromo-3-nitrobenzene ( o-Bromonitrobenzene)

Molecule 7.

1. Main chain: benzene
2. Numbering: Starts at bromine (alphabetical preference over chlorine)
3. Substituents: bromo in 1 and chlorine in 4 (position para)
4. Name: 1-Bromo-4-chlorobenzene (p -Bromochlorobenzene)

Molecule 8.

1. Main chain: benzene
2. Numbering: lowest possible locants to chlorines.
3. Substituents: chlorine in position 1,3 .
4. Name: 1,3-Dichlorobenzene (m-Dichlorobenzene)