Problem 76 - A Complete Resource Book in Chemistry for JEE Main

Question

Write the IUPAC name of the following compound. CCOC(=O)c1ccccc1C(=O)Cl (a) ethyl-2-(chlorocarbonyl) benzoate (b) ethyl-2-(chlorocarbonyl) hexanoate (c) 2-(ethoxycarbony1) benzoyl chloride (d) none of these

Step-by-Step Solution

Answer

The IUPAC name of the compound is ethyl-2-(chlorocarbonyl) benzoate, matching option (a).

Step 1: Identify the main functional group

The structure contains both an ester and an acyl chloride functional group. The ester group, denoted by `COOC`, is the main functional group because it is listed first in the name suggestion and appears first from left to right in the structure.

Step 2: Identify and name the ester part

The ester part of the compound is `CCOC(=O)`. This corresponds to an ethyl ester, because the `CCO` part is an ethyl group attached to the carbonyl (C=O).

Step 3: Determine the base benzene ring

The ester group connects to a phenyl ring (benzene), as indicated by the `c1ccccc1` notation, forming a benzoate structure. This means the base name will be benzoate.

Step 4: Identify substituents on the benzene ring

The benzene ring also has a carboxylic acid chloride group `(C(=O)Cl)`. This group is referred to as `chlorocarbonyl`. It is present at the 2-position (ortho position) on the benzene ring count from the linkage to the ester.

Step 5: Assemble the IUPAC name

The complete IUPAC name will incorporate the ethyl group of the ester and the position of the chlorocarbonyl group. Thus, the compound's IUPAC name is "ethyl-2-(chlorocarbonyl) benzoate."

Key Concepts

Functional Groups

In organic chemistry, a functional group is a specific group of atoms within a molecule that is responsible for the characteristic reactions of that molecule. They are the reactive parts of organic molecules and dictate how a molecule will behave in chemical reactions.
These groups are crucial for determining the properties and reactivity of organic compounds.

• Functional groups can include alcohols, carbonyls, carboxylic acids, ethers, and many more.
• In the given chemical structure, an ester group (`COOC`) and an acyl chloride group (`C(=O)Cl`) are identified.

Understanding functional groups can help predict the reactivity of a compound. In the compound from the exercise, the ester group is the primary focus due to its position and significance in naming according to IUPAC rules.

Ester Compounds

Ester compounds are a prominent class of organic molecules characterized by the presence of an ester functional group. This group comprises a carbon atom double-bonded to an oxygen atom and single-bonded to another oxygen atom that is also bonded to a carbon (R-COOR').
Esters are commonly associated with pleasant fragrances and are found in fats and oils.

• The ester functional group can be identified by `COOR`, where R groups are variable substituents that give diversity to ester molecules.
• In the SMILES notation `CCOC(=O)`, this identifies an ethyl ester, which contributes to its naming.

In IUPAC nomenclature, the alkyl part of the ester is named first, followed by the name of the acid portion with the suffix '-oate'. For example, 'ethyl benzoate' indicates an ethyl group and a benzoate (from benzoic acid) structure.

Benzene Derivatives

Benzene derivatives are compounds where one or more hydrogen atoms in the benzene ring are replaced with other atoms or groups, leading to a variety of different structures and functions.
Benzene, with its unique stability, can form a wide array of derivatives.

• The basic structure is a hexagonal ring with alternating double bonds, noted as `c1ccccc1` in SMILES notation for benzene.
• Substituents, like the `chlorocarbonyl` group `(C(=O)Cl)`, are counted from the point of attachment to name the compound correctly.

In the IUPAC name ethyl-2-(chlorocarbonyl) benzoate, the substituent is at the 2-position, indicating its attachment in relation to the primary functional group, following the ortho- nomenclature for adjacent positions in the ring.