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Chemguide: Support for CIE A level Chemistry Learning outcome 34: Nitrogen compounds 34.3: Amides Learning outcome 34.3.1 This statement is about the formation of amides from the reactions between acyl chlorides and ammonia or primary amines. Before you go on, you should find and read the statement in your copy of the syllabus. Important background Start by reading the page introducing amides. Making amides from an acyl chloride Read the page the reaction of acyl chlorides with ammonia and primary amines. In the first instance, stop when you get to the end of the section about the reaction of an acyl chloride with ammonia. You will need to know the equation for the reaction. Make sure you understand the formation of simple amides like ethanamide before you go on to the rest of the page. Warning! CIE expect you to give an equation for the the formation of an amide and HCl. Do not include the follow-up reactions between excess ammonia and the HCl in this ammonia case or the next one with primary amines.Now continue to the reactions with methylamine and phenylamine to produce N-substituted amides. I haven't given the initial reaction involving the formation of HCl in the phenylamine case, that would be:
My feeling is that you are more likely to be asked about the formation of these than about simple amides. You must expect to be given a formula for a complicated molecule which may contain one or more amino groups. You will then be asked to draw the structure of the product after reaction with ethanoyl chloride. Provided you understand what is happening with methylamine or phenylamine, there is no real problem about this, even though the molecules look more scary. All you are doing is replacing a hydrogen atom in the amine by a CH3CO group. If you have more than one amino group in your molecule, you mustn't forget to do this with all of them.
© Jim Clark 2020 |
