Q9 · CSIR-NET Chemistry, December 2019
Paper: CSIR-NET December 2019 · Subject: Organic Chemistry · Chapter: General Organic Chemistry · Topic: General Organic Chemistry – General · Marks: 2 · Difficulty: Medium
The correct order for the rate of thermal decarboxylation of the following compounds is 
A B C
A B C(a)$\mathrm{C}>\mathrm{B}>\mathrm{A}$
(b)C $>$ A $>$ B
(c)A $>$ C $>$ B
(d)$\mathrm{B}>\mathrm{C}>\mathrm{A}$
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
2-Pyridylacetic acid (C) decarboxylates most easily, through a cyclic zwitterion giving an enamine. Picolinic acid (B) loses CO₂ via the Hammick ylide. Benzoic acid (A) is very resistant. C > B > A (a).
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