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Amides can be prepared from carboxylic acid or acid halides by reaction with amines. When we change the amine type (primary, secondary and tertiary) we can get different amide types. But here we are going to prepare N-propylethanamide from ethylbromide. Reaction of carboxylic acid chloride and amine is the best way to prepare amides.
Mixing propanamine and ethanoyl chloride will give N-propylethanamide. So we have to prepare propanamine and ethanoyl chloride using ethylbromide separately. Therefore we use two paths.
In one step, we first prepare ethnaol, then ethnoic acid(CH3COOH) and finally ethanoyl chloride(CH3COCl).
In other step, first prepare propionitrile(CH3CH2CN)and then propanamine(CH3CH2CH2NH2).
All required reagents are noted in the following image.