Question:
Which from following amines does NOT form alkyl isocyanide when heated with alc. KOH and chloroform
Which from following amines does NOT form alkyl isocyanide when heated with alc. KOH and chloroform
Show Hint
Only primary amines give isocyanides.
Updated On: Oct 1, 2026
- Methanamine
- Propan-2-amine
- N, N-Diethylethanamine
- Ethanamine
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Understanding the Concept:
The carbylamine (isocyanide) test works only for primary amines. When heated with chloroform and alcoholic KOH, \(\text{R-NH}_2\) gives the foul smelling isocyanide \(\text{R-NC}\).
Step 2: Key Formula or Approach:
Classify each amine: methanamine, ethanamine and propan-2-amine are primary. \(N,N\)-Diethylethanamine, \((\text{C}_2\text{H}_5)_3\text{N}\), is tertiary.
Step 3: Detailed Explanation:
The reaction needs two N-H hydrogens to be removed with the dichlorocarbene formed from \(\text{CHCl}_3\) and KOH.
\[ \text{R-NH}_2 + \text{CHCl}_3 + 3\text{KOH} \to \text{R-NC} + 3\text{KCl} + 3\text{H}_2\text{O} \]
A tertiary amine has no N-H, so it cannot form an isocyanide.
Final Answer:
\(N,N\)-Diethylethanamine does not form an isocyanide, option (C). \[ \boxed{N,N\text{-Diethylethanamine}} \]
The carbylamine (isocyanide) test works only for primary amines. When heated with chloroform and alcoholic KOH, \(\text{R-NH}_2\) gives the foul smelling isocyanide \(\text{R-NC}\).
Step 2: Key Formula or Approach:
Classify each amine: methanamine, ethanamine and propan-2-amine are primary. \(N,N\)-Diethylethanamine, \((\text{C}_2\text{H}_5)_3\text{N}\), is tertiary.
Step 3: Detailed Explanation:
The reaction needs two N-H hydrogens to be removed with the dichlorocarbene formed from \(\text{CHCl}_3\) and KOH.
\[ \text{R-NH}_2 + \text{CHCl}_3 + 3\text{KOH} \to \text{R-NC} + 3\text{KCl} + 3\text{H}_2\text{O} \]
A tertiary amine has no N-H, so it cannot form an isocyanide.
Final Answer:
\(N,N\)-Diethylethanamine does not form an isocyanide, option (C). \[ \boxed{N,N\text{-Diethylethanamine}} \]
Was this answer helpful?
0
0
Top MHT CET Chemistry Questions
- The temperature of $32^{\circ}C$ is equivalent to
- The heat of formation of water is $ 260\, kJ $ . How much $ H_2O $ is decomposed by $ 130\, kJ $ of heat ?
- If a metal crystallises in bcc structure with edge length of unit cell $4.29 \times 10^{-8}\, cm$ the radius of metal atom is
- Which of the following oxides can act both as an oxidising agent as well as reducing agent ?
- "The mass and energy both are conserved in an isolated system", is the statement of
View More Questions
Top MHT CET Amines Questions
- Identify the product 'C' in the following reaction. $\ce{Aniline ->[(CH_3 CO)_2 O][Pyridine] A ->[Br_2][CH_3COOH] B ->[H^{+} or \, OH^{-}] C }$
- In the following reaction sequence, Ethyl amine $ \ce{->[HNO_2]} A \ce{->[PCl_5]}B \ce{->[NH_3]} C $ the compound $ 'C' $ is
- Which of the following statements is INCORRECT in case of Hofmann bromamide degradation ?
- Which of the following reactions will not give a primary amine?
- The most reactive amine towards dilute hydrochloric acid is:
View More Questions
Top MHT CET Questions
- During r- DNA technology, which one of the following enzymes is used for cleaving DNA molecule ?
- In non uniform circular motion, the ratio of tangential to radial acceleration is (r = radius of circle, $v =$ speed of the particle, $\alpha =$ angular acceleration)
- The temperature of $32^{\circ}C$ is equivalent to
- The line $5x + y - 1 = 0$ coincides with one of the lines given by $5x^2 + xy - kx - 2y + 2 = 0 $ then the value of k is
- The heat of formation of water is $ 260\, kJ $ . How much $ H_2O $ is decomposed by $ 130\, kJ $ of heat ?
View More Questions