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CHEMISTRY, M7 2024 HSC 12 MC

The structure of an organic substance is shown.
 

   

What is the preferred IUPAC name for this substance?

  1. 2-chloro-1-ethylbutanamide
  2. 2-chloro-\(N\)-ethylpropanamide
  3. 3-chloro-\(N\)-ethylbutanamide
  4. 3-chloro-1-ethylpropanamide
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\(\Rightarrow C\)

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Compound is a secondary amide.

  • Pre-fix (longest carbon chain) \(\Rightarrow\) -butan
  • Suffix (functional group) \(\Rightarrow\) -amide, 
  • Alkyl chain bound to the amide nitrogen is treated as a substituent and as it is bound to the nitrogen atom \(\Rightarrow\) \(N\)-ethyl
  • As the amide group has the highest priority for the naming of the compound, carbon 1 is the carbon with the nitrogen and oxygen atom attached to it.
  • Hence, the chlorine atom is attached to carbon 3.
  • Compound name is 3-chloro-\(N\)-ethylbutanamide

\(\Rightarrow C\)

CHEMISTRY, M7 2021 HSC 3 MC

The structure of a compound is shown.
 


 

What is the preferred IUPAC name of this compound?

  1. `N`-methylpropanamide
  2. `N`-methylpropanamine
  3. `N`-propanylamine
  4. `N`-propylmethanamide
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`A`

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Compound is a secondary amide.

  • Pre-fix (longest carbon chain) → -propan
  • Suffix (functional group) → -amide
  • Alkyl chain bound to the amide nitrogen is treated as a substituent and as it is bound to the nitrogen atom → `N`-methyl
  • Therefore, compound name is `N`-methylpropanamide

`=>A`