Plan out a 4 step organic synthesis to form N-methyl Butanamide from 1-Bromopropane. Include relevant reagents and conditions for each reaction. Include 1 mechanism for one of the stages.

A Level

The chain length needs to be extended by 1, so we can use NaCN dissolved in ethanol to extend the carbon chain by 1. This will produce butanenitrile. Mechanism here.2) Now that the nitrile is formed, we can start to get towards the acyl chloride that we need to make the amide. This can be done by first forming a carboxylic acid. Heat dilute aqueous acid (such as HCl) with butanenitrile to hydrolyse the nitrile, and form its respective carboxylic acid. (Mechanism not possible for A-Level here)3) Upon forming the carboxylic acid, reflux the product with SOCl₂/thionyl chloride to form the acyl chloride of butanoyl chloride (Mechanism not possible here)4) Now using the formed butanoyl chloride, use methylamine and react it with the acyl chloride to form the wanted product. Mechanism here