Q5 · CSIR NET Chemistry, December 2014
Paper: CSIR NET December 2014 · Subject: Organic Chemistry · Chapter: General Organic Chemistry · Topic: Acidity Basicity · Marks: 2 · Difficulty: Hard
The decreasing order of basicity of the following compounds is 
(I) (II) (III) (IV)
(I) (II) (III) (IV)(a)I $>$ II $>$ III $>$ IV
(b)IV $>$ I $>$ II $>$ III
(c)III $>$ II $>$ I $>$ IV
(d)IV $>$ III $>$ II $>$ I
Answer
Answer: C ✓ checked by 4AB · confidence high
Explanation
The bicyclic guanidine (III, TBD-type, pKa ≈ 15–26) > the bicyclic amidine (II, DBN-type, ≈ 13) > imidazole (I, 7.0) > pyridine (IV, 5.2) (c).
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