Mechanism of 1-iodobutane reacts with pyridine

It is an example of elimination reaction through the E2 mechanism.

Explanation:

The reaction between 1-iodobutane and pyridine is an example of an E2 (bimolecular elimination) elimination reaction.

Pyridine acts predominantly as a base and the given alkyl halide is a primary alkyl halide. Both of these two factors facilitate the E2 mechanism.

Here, both H and Cl are eliminated in a single step to produce 1-butene as the product of the reaction.

The reaction mechanism and the structure of the product are shown below.