Question

Identify 2-propoxybenzene from the following options:

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

Always look closely at the branching number on the alkyl name! "1-propoxy" indicates a straight tail linkage ($\text{-O-CH}_2\text{-CH}_2\text{-CH}_3$), whereas "2-propoxy" means it links right at the middle vertex ($\text{-O-CH(CH}_3)_2$).

Answer 1

The Correct Option is B

Step 1: Break the name into pieces.
The name 2-propoxybenzene has two parts: benzene as the parent ring and a propoxy group ($-\text{O-C}_3\text{H}_7$) attached to it through oxygen, making this an aryl alkyl ether.
Step 2: Interpret the locant on the propyl chain.
The number 2 tells us that the oxygen is bonded to the second (middle) carbon of the three-carbon propyl chain, not the end carbon.
Step 3: Translate that into a structure.
Oxygen bonded to the middle carbon of propane gives the isopropoxy group, $-\text{O-CH(CH}_3)_2$. So the target is benzene-O-CH(CH$_3)_2$, that is isopropoxybenzene.
Step 4: Recognise what to reject.
If oxygen were on the end carbon we would have 1-propoxybenzene (a straight $-\text{O-CH}_2\text{CH}_2\text{CH}_3$ chain), which is a different compound and must be ruled out.
Step 5: Scan the option structures.
We look for the structure where the ring-O links to a carbon that itself carries two methyl groups (a secondary carbon). That branching pattern is the signature of the isopropoxy group.
Step 6: Pick the match.
Option (2) shows the oxygen joined to a CH that bears two CH$_3$ groups, exactly the isopropoxy (2-propoxy) linkage on benzene.
\[ \boxed{\text{2-propoxybenzene = option 2}} \]