Question

Alkyl halides are formed when thionyl Chloride and __ are refluxed in presence of pyridine. The order of reactivity $(3^o>2^0>1^0)$ is due to the +I effect of the alkyl group which ____________The polarity of CX bond.

• A. acids, decreases
• B. alcohol, increases
• C. aldehydes, changes
• D. ketones, decreases

Answer 1

Answer: (B)

alcohol, increases

The reaction of thionyl chloride and alcohol in presence of pyridine is called as Darzen's reaction. The pyridine acts as a catalyst and this way alkyl halides are formed. the order of reactivity $3^{\circ }>2^{\circ }>1^{\circ }$ is due to the +I effect of the alkyl group which increases the polarity of CX bond. The CX bond determines the reactivity of the compound.